Gre Tunnel Line Protocol Down

In this example, we will create secure connection using SSH and local port fowarding. Remember, you don't need to configure your tunnel mode and transport protocol because GRE and IP are the defaults. Tunnel 199 is up line protocol is up. R2 Tunnel14 is up, line protocol is down Hardware is Tunnel Description: to_nabcheln_r01 Internet address is 192. 1 YES TFTP up down On the crypto headend side, the corresponding virtual access interface for this branch shows down/down when. Exploring Generic Routing Encapsulation (GRE), the first step in tunneling. Question 3. Tunnel0 is up, line protocol is down Hardware is Tunnel Internet address is 192. From the output, we see the the line "Serial0/1 is up, line protocol is up". 1/24 MTU 1514 bytes, BW 9 Kbit, DLY 500000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive not set Tunnel source 202. Cisco ASA firewall will redirect intercepted HTTP and HTTPS traffic to proxy box using GRE tunnel. Nighthawk X6 R8000 GRE (protocol) forwarding. GRE (Generic Route Encapsulation) is a protocol that "carries" other passanger protocols - for example, IP multicast, which allows us to run routing protocols; with GRE over IPsec, all traffic between GRE endpoints is encrypted by IPsec; this scenarios uses the method of crypto-maps - only one line in the crypto ACL is enough: the GRE protocol. The router then sends that packet through the tunnel, which results in its encapsulation with the outer IP header, and a GRE header with the PT of IP. A consequence of this is that, by default, the local tunnel endpoint router does not have the ability to bring the line protocol of the GRE Tunnel interface down if the remote end of the tunnel is unreachable. 1/31, MTU 1476 bytes, encapsulation GRE Keepalive is not Enabled Path MTU Discovery: Enabled, MTU is 1428 bytes. A GRE tunnel is used when packets need to be sent from one network to another over the Internet or an insecure network. a) phase 1. ENSP做IPsec over GRE 后Line protocol current state : DOWN 的问题 tunnel-protocol gre interface Tunnel 0/0/1 进入 GRE. And while the level of security PPTP provides has. In P2MP GRE tunnel mode, both the transport protocol and passenger protocol are IPv4. The GRE is a protocol designed for performing tunneling of a network layer protocol over another network layer protocol. iproute2 is a package for advanced network management under linux. ESP or encapsulated (e. Netfilter is a kernel module, built into the kernel, that actually does the filtering. 1/31, MTU 1476 bytes, encapsulation GRE Keepalive is not Enabled Path MTU Discovery: Enabled, MTU is 1428 bytes. You can configure a GRE Generic Routing Encapsulation. By default, a GRE tunnel is protocol up, if the physical interface is up/up and there is a route to the GRE destination; If the far side of the GRE tunnel is not configured or down, this will cause a black-hole for traffic; In order to ensure end-to-end reachability, keepalives are used (off by default) Configuration. Line Protocol Down Locally on the Router. The keepalive is double-encapsulated, so the remote peer receives the keepalive, decapsulates it, and is 'tricked' into sending the response. Typically, GRE tunnel is encapsulated inside the IPSec tunnel and this model is called GRE over IPSec. A major benefit associated with IPSec virtual tunnel. 配置 Dynamic p2p GRE over Ipsec 配置 GRE 隧道 (1)在 R2 上配置终点为 R3 的 p2p GRE 隧道 R2(config)#int tunnel 23 R2(config-if)# *Mar 1 01:46:43. Generic Routing Encapsulation (GRE) Tests¶. The only thing that changed in the get vpn 2nd output was on the last line: U 10. No Internet means no email, no web browsing and in many cases, no work. On the 6th spoke, a 2911, we have created a Tunnel0. Tunnel 199 is up line protocol is up. OSPF is enabled on this interface. Usable bandwidth is much higher compared with a leased line or a multiprotocol label switching (MPLS) link at the same price, and big keys or certificates can achieve a high level of security. 当 RTA 链路出现问题时,切换到备用 RTB 上,保持 GRE VPN 不断, PC 可以快速访问到备用服务器;. 121 This creates a GRE tunnel between the local interface 9. RA: Tunnel0 is up, line protocol is up (connected) Hardware is Tunnel Internet address is 192. November 19, 2014 VPN - GRE over IPsec. This means that each tunnel end-point does not keep any information about the state or availability of the remote tunnel end-point. Each router r1 through r5 will physically connect to a common FDDI ring. the senerio is. down/down—The tunnel and line protocol are down. 1/24 MTU 1514 bytes, BW 9 Kbit/sec, DLY 500000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive not set Tunnel source 192. 113 ttl 255 ikey 0x111111 okey 0x222222 csum seq $ sudo ip addr add 10. CCNA Security - GRE Tunnel (include HSRP also) ip forward-protocol nd ! line con 0 exec-timeout 0 0 privilege level 15 logging synchronous line aux 0 exec. GRE tunnel not working. Tried with service-loopback binded to physical interface but still tunnel is showing down down. tunnel mode gre multipoint. 37 (the router Y at the other end), that our tunneling packets should originate from 169. #line console 0 R1 (config-line) #password cisco R1 Display the protocol using the highest volume of traffic. I follow an exemple on the cisco site, it works! BUT, there is a big but, each lan on the two side can "see" the other execpt the router itself !. 4 YES TFTP up up Virtual-Template11 172. OSPF is enabled on this interface. I simulated this in gns3, the moment you add 'tunnel mode ipv6' on the tun34 int on R4, its line protocol goes down. 4 ip mtu 1438 ip link set gre1 up. a) phase 1. In the most general case, a system has a packet, that needs to be encapsulated and delivered to some destination, which is called payload. GRE over IPv4 tunneling driver. You can't have a destination to a GRE tunnel that hasn't been established yet. RTA 、 RTB 使用 VRRP 虚地址与 RTC 起 GRE Tunnel 。 3. The GRE tunnel configured in the following case is carrying IP traffic and is using a source IP address of 10. Here this output is showing that the protocol used for the tunnel is GRE/IP and transfer MTU is of size 1476 bytes which is 4 bytes lesser than IPv6IP. Ospf Authentication on Cisco IOS XR line protocol is up Cisco Ipsec over Gre Tunnel Configuration Example In this example we will test ipsec over gre tunnel. + The interface that anchors the tunnel source is down. 255 Ethernet0 As a side note, is this (GRE tunnel through the PIX) a good design from the security point of view?. We recreated the problem in our lab and it consistently failed. When I do a show interface, it shows tunnel up, but line protocol down. Open-standard IPSec Protocol suite, in transport mode. up/down) and. Line protocol current state : DOWN Description:HUAWEI, Tunnel1/1/4001 Interface Route Port,The Maximum Transmit Unit is 1500 Internet Address is 192. Acronyms and Terminology GRE: Generic Routing Encapsulation [RFC2784] [RFC2890]. As it is a logical interface it will never go down. Interesting. Information About IPSec Virtual Tunnel Interfaces: The IPSec virtual tunnel interface greatly simplifies the configuration process when you need to provide protection for remote access and provides an simpler alternative to using GRE or L2TP tunnels for encapsulation and crypto maps with IPSec. A Generic Routing Encapsulation (GRE) tunnel is a non-secure, site-to-site VPN tunneling solution that is capable of encapsulating any Layer 3 protocol between multiple sites across over an IP internetwork. The GRE tunnel is taken down and will continue flapping. GRE is used to create a tunnel so that it appears as one link from source to destination. Select Custom settings > One VPN tunnel per Gateway pair. Information about…. Bottom line, for any VPN that is NOT encapsulated inside UDP. 67 RouterD# sh int s0 Serial0 is up, line protocol is up Hardware is 68 LAB 7 unset administratively down down FastEthernet0/1 10. A network management system comprises generic routing encapsulation (GRE) logic configured to establish upon request one or more GRE tunnels from one or more network interfaces; routing protocol. GRE Keepalives. If you select both IPsec and GRE encapsulations, two TLOCs are created for the tunnel interface that have the same IP addresses and colors, but that differ by their encapsulation. A consequence of this is that, by default, the local tunnel endpoint router does not have the ability to bring the line protocol of the GRE Tunnel interface down if the remote end of the tunnel is unreachable. - create static route (better AD) to other side of tunnel (on both routers) that point through physical interface - make route through tunnel looks worse to reach other side of tunnel (you could use offset list - to make cost through tunnel worse than through physical interface) - make in EIGRP - passive-interface tunnel 100. GRE tunnels are traditionally used for unencrypted IP in IP tunneling. I also have other GRE tunnels going from the same HP5510 to different MSR's which are working fine, config is replicated, so this is odd. DMVPN - phase four (IKEv2/FlexVPN) When Cisco introduced the new IKE (IKEv2) and the new unified configuration for all types of VPN (excluding GET VPN), they also updated the DMVPN. -Transport mode will protect any traffic that is locally sourced from the configured IPsec tunnel interface as "transport mode" traffic. As shown in the figure, two GRE tunnels are configured between the gateway WAN port, fa4, which has a static public IP address, 192. ip tunnel add gre1 mode gre key 1234 ttl 64 ip addr add 10. 255 Source Y. There are a couple of advantages to using a Loopback interface instead of a physical interface [5]. Cisco ASA firewall will redirect intercepted HTTP and HTTPS traffic to proxy box using GRE tunnel. The Tunneling Process. 2/24 MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec,. IP or MPLS) over another arbitrary network layer protocol. keep alive 5 4 - where 5 in this case is the frequency and 4 is the retry before considerd down LAB 1 General Gre tunnel line protocol is up Hardware is Tunnel. Using a GRE tunnel reduces the maximum transfer unit (MTU) for the path by the overhead of GRE encapsulation. GRE tunnels in particular are far easier to configure and scale out versus using IPsec in tunnel mode to handle routing. At site #2, look at the config of Tunnel10, look for the tunnel destination a. While it is a Cisco developed protocol, it is also defined in several RFCs (1701, 1702 and 2784). [HELP] Gre Tunnel Protocol Down. KB ID 0000954 Dtd 09/06/14. 1/31, MTU 1476 bytes, encapsulation GRE Keepalive is not Enabled Path MTU Discovery: Enabled, MTU is 1428 bytes. 当 RTA 链路出现问题时,切换到备用 RTB 上,保持 GRE VPN 不断, PC 可以快速访问到备用服务器;. If you do change it to a gre tunnel, note that gre keepalives are not supported with "tunnel protection" IPSEC (remove keepalive statement under the tunnel or it will never come up/up). If the rest of the command line does not give enough information to guess the family, ip falls back to the default one, usually inet or any. down/down—The tunnel and line protocol are down. When the router goes to encapsulate it in the GRE tunnel it has to add another 40 byte header. The red line shows the relationship form by stacking the two sub-graphs. DMVPN prevents the need for pre-configured (static) IPsec (Internet Protocol Security) peers in crypto-map configurations and ISAKMP (Internet Security Association and Key Management Protocol) peer statements. Y Destination X. The line protocol on a GRE tunnel interface is up as long as there is a route to the tunnel destination. I simulated this in gns3, the moment you add 'tunnel mode ipv6' on the tun34 int on R4, its line protocol goes down. Cisco Bug: CSCvc78926 - GRE tunnel is up but line protocol is down with GRE tunnel keepalive configuration on CRS Topaz. GRE is used to create a tunnel so that it appears as one link from source to destination. 8 Tunnel protocol/transport GRE/IP, key disabled, sequencing. GRE Tunnel Protocol Down - Any help would be Awesome See the attached: Cant figure out why the tunnel had a 'down' protocol. This document makes this protocol available to the public, thereby enabling other developers to build interoperable implementations. conf and change the content to the following (replace strongpassword with a password of your choice and %HUB_GRE_IP% with the Hub node GRE IP address): Add the line neighbor %HUB_GRE_IP% remote-as 65000 for each Hub host you have in your NBMA cloud. A The GRE tunnel source and destination addresses are specified within the from MATHEMATIC ALGEBRA 3 at Three Rivers High School. In this example, we will create secure connection using SSH and local port fowarding. Those seeking additional information on available DMVPN deplyment models can also visit my Dynamic Multipoint VPN DMVPN Architecture article. The red line shows the relationship form by stacking the two sub-graphs. Can you please help me with the setup here. 1 (Vlan200), destination 10. Tunnel0 is up, line protocol is up. IPSec AH and ESP). I have a GRE tunnel that is running between a Comware 5510HI and MSR954. In Cisco IOS Software Releases 15. iproute2 is a package for advanced network management under linux. 2 Tunnel protocol/transport GRE/IP, key disabled keepalive disabled. when i do a sh crypto isakmp sa the session is status active, there is a valid route available to the remote end, but tunnel interface shows line protocol down. 70 and the remote interface 9. This can lead to routing blackholes. 1/30 Encapsulation is TUNNEL, loopback not set Tunnel source 192. using gre for more reliable backup routes Today I also looked at using gre for backup interface specfically using the keep alive feature. Generic routing encapsulation tunnel encapsulates data within a packet that needs to be delivered to destination. Type in the mean values of MR signal given by ROIs, up to three for the liver and one or two for the paraspinal muscles. PDF | Generic Routing Encapsulation (GRE) Status of this Memo This memo provides information for the Internet community. The two endpoints are identified by the tunnel source and tunnel destination addresses at each endpoint. Generic Routing Encapsulation (GRE) tunnels work just like a serial link, with virtual tunnel interfaces replacing physical serial interfaces. display ip interface brief *down: administratively down ^down: standby (l): loopback (s): spoofing (E): E-Trunk down The number of interface that is UP in Physical is 3 The number of interface that is DOWN in Physical is 4 The number of. * Use an alternative like Secure Shell [SSH] and a free SFTP client like WinSCP or Tunnelier for secure remote access to files and folders or Remote Desktop access/control of PCs on the office LAN. Therefore the local tunnel endpoint does not bring the line protocol of the GRE tunnel interface down if the remote tunnel endpoint is unreachable. The loopback route (9. But then I realized that that GRE tunnel in itself is a new feature as well, which the release notes don't really […]Share the wealth!. We could run a protocol scanner to find hosts running GRE. All fu(ket up packets are GRE protocol + tcp PPTP port 1723. Cisco Nexus Switch Basic CLI Commands I recently visited Perth Western Australia for a core switch upgrade project and it was cold and rainy during my stay there. GRE (on vEdge routers) Use GRE encapsulation on the tunnel interface. This scenario is a routing issue that sometimes occurs when an interior routing protocol allows routes to leak back through a tunnel. Page 89: Creating A Secure Gre Tunnel Click Enable to enable the configuration and complete the following: For GRE Tunnel Information Interface Name Enter the name of the interface to connect to tunnel. 2/24 MTU 1514 bytes, BW 9 Kbit, DLY 500000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive not set Tunnel source 61. configure terminal ! interface GigabitEthernet 0/1 no ip address pppoe enable group global pppoe-client dial-pool-number 10 exit ! interface GigabitEthernet 0/0 ip tcp adjust-mss 1356 exit ! interface Loopback 1 ip address 106. On Sale NetScout CSN/NTM-PO2B-10PA. Light at the end of the tunnel: PM to open Bidar-Kalaburagi rail line. Navigate to the VPN > VPN Advanced page of the interoperable object (Cisco device). En artículos anteriores hemos visto los túneles GRE, hoy vamos a ver el routing recursivo, una pifia habituál a la hora de trabajar con túneles GRE. I have a question, in this case you have only one link between the L3 switch and the ASA and default route its fine, how would you do it in case you have two ASAs pointing to a two different ISPs but you want that users in all vlans use both links,ex: one link is internet and the other is a MPLS to a remote location, all user need access to. e ip any any. The GRE tunnel configured in the following case is carrying IP traffic and is using a source IP address of 10. Views Tunnel interface view Predefined user roles network-admin Parameters. Line protocol current state : DOWN Description:HUAWEI, Tunnel1/1/4001 Interface Route Port,The Maximum Transmit Unit is 1500 Internet Address is 192. 0 crypto isakmp keepalive 10 ! crypto ipsec transform-set TRANSF esp-3des esp-sha-hmac ! crypto ipsec profile PROFILE set transform-set TRANSF…. The GRE tunnel can show "tunnel down and line protocol up" in the following scenarios: Cannot find destination route or route points to Management Interface; Configured Keepalive is down; If the source IP is loopback/VE and if IP interface is disabled; Source IP is physical port and physical port is not up. 2 Tunnel protocol/transport GRE/IP, key disabled keepalive disabled. A Citrix Cloud Connector tunnel uses the following protocols: Generic Routing Encapsulation (GRE) protocol. Thus a link going down on one end doesn't have the capability of bringing down the line protocol on the other end. In any case, in the current execution of GRE shafts, an arranged shaft does not can cut down the line convention of either passage endpoint, if the far end is inaccessible. This is probably too simple for some. 2/24 MTU 1514 bytes, BW 9 Kbit, DLY 500000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive not set Tunnel source 61. Cisco CCNA GRE Tunnel Configuration 1. Use EIGRP 123 as routing protocol. 53/30 MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive not set Tunnel source 172. GRE encapsulation uses a protocol-type field in the GRE header to support the encapsulation of any OSI layer 3 protocol. Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 192. The GRE protocol provides a mechanism for encapsulating packets, from a wide variety of network protocols, to be forwarded over another protocol. Configuring 6to4 Tunnels This was the last ROUTE lab I did for IPv6, which is about 6to4 Tunneling. GRE supports broadcast and multicast B. Running head: CONFIGURE, VERIFY, AND TROUBLESHOOT GRE TUNNEL CONNECTIVITY 1 Configure,. Netfilter is a kernel module, built into the kernel, that actually does the filtering. MikroTik now provides hardware and software for Internet connectivity in most of the countries around the world. e ip any any. Two WCCP services must be used, one for outgoing traffic and an inverse for return traffic from the Internet. GRE Keepalives. A Generic Routing Encapsulation (GRE) tunnel is a non-secure, site-to-site VPN tunneling solution that is capable of encapsulating any Layer 3 protocol between multiple sites across over an IP internetwork. The GRE tunnel is created first, then ipsec is used to encrypt the content of the tunnel. 10 Tunnel destination is 1. We added a tunnel interface, and created a GRE tunnel between the infrastructure loopbacks; We added a route to make the customer subnet reachable over the tunnel. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions. (Anu3600) #show interface tunnel 10. A consequence of this is that the local tunnel end-point router does not have the ability to bring the line protocol of the GRE tunnel interface down if the remote end-point is unreachable. ipv6 route 2::/64 tunnel 0! R3#sh ip int tun0 Tunnel0 is up, line protocol is down Internet protocol processing disabled R3# R2# ping 3::3 repeat 2 source 2::2 Type escape sequence to abort. Configure GRE Tunnel on Ubuntu 18. After we have a GRE tunnel set up between two endpoints, and an interface for mirrored traffic to ensure that no mirrored traffic is routed on the linux (virtual) machine, an unused GRE Ethernet tunnel can be tested by running ping on one end and tcpdump on the other to see the GRE tunnel traffic. Cisco WAN :: 2911 - DMVPN Tunnel 0 Up - Line Protocol Down Jul 8, 2011. Option about IPSec. Other spokes and hubs can ping this router's Tunnel 0 IP, but it can't ping itself. 2 Tunnel protocol/transport GRE/IP, key disabled, sequencing disabled Tunnel TTL 255. Hi, I have configured configued our company's Cisco 871W per suggested configs, found here and on the cisco web site, however, VLAN1, VLAN10 and VLAN20 interfaces won't come up (e. display ip interface brief *down: administratively down ^down: standby (l): loopback (s): spoofing (E): E-Trunk down The number of interface that is UP in Physical is 3 The number of interface that is DOWN in Physical is 4 The number of. More union gre_tunnel_key_t_ Union of the two possible key types. Generic Routing Encapsulation (GRE) is a tunneling protocol that encapsulates network layer protocols inside virtual point-to-point links over an Internet Protocol network. I am not sure if it is with the GRE or the IPSec tunnel. Something seems to be significantly slowing down the traffic. By default, a GRE tunnel is protocol up, if the physical interface is up/up and there is a route to the GRE destination; If the far side of the GRE tunnel is not configured or down, this will cause a black-hole for traffic; In order to ensure end-to-end reachability, keepalives are used (off by default) Configuration. docx from CIT 276 at University of Phoenix. Now as luck would have it I stumbled across a bug with tunnel interfaces miscalculating the IP mtu after the router is rebooted. HP A-Series Switches - How to Configure a Generic Routing Encapsulation (GRE) Over IPv4 Tunnel Information Tunneling is an encapsulation technology, which utilizes one network protocol to encapsulate packets of another network protocol and transfer them over the network. 模拟器配置VPN,GRE管道,公网IP是通的,可是Tunnel0/0/1协议DOWN,2边路由器的Tunnel都是一样的DOWS。. 123 ttl 255 ikey 0x222222 okey 0x111111 csum seq. Generic Routing Encapsulation (GRE) tunnels work just like a serial link, with virtual tunnel interfaces replacing physical serial interfaces. If there is a way to reach the far end tunnel endpoint, and the tunnel line protocol is not down due to other reasons, the packet arrives on Router B. NET: Registered protocol family 1. tunnel over IPv6 between an Instant AP and a GRE Generic Routing Encapsulation. پس چنانچه در چند بازه زمانی، فرستنده مکانیزم keep-alive پاسخ را دریافت نکند، line protocol اینترفیس Tunnel خود را down می نماید. device # show interface tunnel 10 Tunnel10 is up, line protocol is up Hardware is Tunnel Tunnel source 1. That point-to-point GRE tunnel is a good solution, but if you have a lot of sites it's not a solution that scales very well. Attempt to ping the IP address of PCA from PCB. 2) MTU 1514 bytes, BW 9 Kbit, DLY 500000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive set (5 sec), retries 3 Tunnel source 10. Protect Your Web Servers from Direct Attack. This GRE tunnel is used to encapsulate all IPv6 traffic (red) from the client. newindianexpress. The ability to mark an interface as down when the remote end of the link is not available is used in order to remove any routes (specifically static routes) in the routing table that use that interface as the outbound interface. The technique issues “keepalive” packets that are returned to the source endpoint by a reachable destination endpoint. 1 Route Port,The Maximum Transmit Unit is 1500 Internet Address is 100. 1/30 MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation TUNNEL, loopback not set Keepalive set (5 sec), retries 4 Tunnel source 2. tunnel-protocol gre p2mp. #create GRE tunnel and bring it up. GRE Tunnel Protocol Down - Any help would be Awesome See the attached: Cant figure out why the tunnel had a 'down' protocol. There was also a question about GRE tunnel with the options of it support multicast, broadcast traffic or only broadcast and some other options that we needed to choose 2 correct ones. Configure GRE over IPsec VPN I've visited many countries mostly in Asia trying to set up client VPN connections and for our Point-of-Presence (POP) connection back to our HQ in Singapore. Un tunel GRE permite conectar dos extremos que tienen conectividad y por tanto routing, haciendo que cuando los paquetes atraviesen el tunel parezca que se trata de un único salto, pero en. If 3 in a row are missed, the tunnel’s line protocol is brought down. To allow packet transmission over GRE tunnels in centralized GRE mode, the mapping between the source tunnel interface and the tunnel service board must be configured, and the target-board command needs to be run to bind the interface to the GRE protocol. - to avoid fragmentation via gre tunnel, 3 command lines in order (choices were like ip mtu 1400, gre mtu discovery, mss. Any idea why this is happening?. This article examines a specific DMVPN deployment architecture. GRE Tunnel 用默认路由建立时将出现down的情况。 Line protocol on Interface Tunnel0, changed state to up (Generic Routing Encapsulation):. The mobileip driver provides IP tunnel construction using the Mobile IP (RFC 2004) encapsulation protocol. Cisco Nexus Switch Basic CLI Commands I recently visited Perth Western Australia for a core switch upgrade project and it was cold and rainy during my stay there. Each router r1 through r5 will physically connect to a common FDDI ring. Otherwise the line protocol will go down. Cisco Simple GRE Tunnels (With IPSEC) R1# show interface tunnel 0 Tunnel0 is up, line protocol is up Hardware is Tunnel Internet address is 10. • Generic Routing Encapsulation (GRE) Transports Layer 2 connectivity over a Layer 3 path in a secured way; enables these aggregation of traffic from site to site Management • Management interface control Enables or disables each of the following interfaces depending on security preferences: console port, telnet port, or reset button. aaa-new model not used and hence policy will not be applied. RULES: Do not use “ip route”command =) Do not change the default HDLC encapsulation in the interfaces;. IP looks up the route to the destination address and learns that it is through the tunnel interface, which returns the packet to Step 1 above; hence, there is a recursive routing loop. It is very simple, when you enable GRE keepalive then GRE will be up on only one condition, when both the devices are able hear the HB then the tunnel will be up otherwise it will be down. configure terminal ! interface GigabitEthernet 0/1 no ip address pppoe enable group global pppoe-client dial-pool-number 10 exit ! interface GigabitEthernet 0/0 ip tcp adjust-mss 1356 exit ! interface Loopback 1 ip address 106. GRE Tunnel is down. Serial000 changed state to up Jun 16 112203507 LINEPROTO 5 UPDOWN Line protocol from CIT 276 at University of Phoenix. it's a sample configuration but the tunnel does not stay UP and after a few seconds I get the message that it has become down. This was actually to be the basis for something called opportunistic encryption, which was originally going to be required in IPv6; yes, everything on IPv6 was going to be automatically encrypted, whether the layer 7 protocol supported it or not. To allow packet transmission over GRE tunnels in centralized GRE mode, the mapping between the source tunnel interface and the tunnel service board must be configured, and the target-board command needs to be run to bind the interface to the GRE protocol. 0 crypto isakmp keepalive 10 ! crypto ipsec transform-set TRANSF esp-3des esp-sha-hmac ! crypto ipsec profile PROFILE set transform-set TRANSF…. Re: GRE tunnel line protocol down on one side only That must mean that Site #2 has no valid route to the IP address of the interface hosting the tunnel at site #1. I have configured a gre tunnel between a branch office and HQ. 4 YES manual up up ===== CONFIGURATION R14#sh run Building configuration. By default, the tunnel mode is GRE over IPv4. Tunnel 199 is up line protocol is up. If 3 in a row are missed, the tunnel's line protocol is brought down. More important are the two GRE interfaces – Both with a tunnel source IP of 192. Other spokes and the hubs can ping it's ip, but it can't ping itself. The introduction of a routing protocol across a GRE tunnel can cause an interesting problem known as recursive routing. Use it if you have to, otherwise use GRE. Also the encapsulation used on this interface is HDLC -> The other end must use the same encapsulation. 1 (Loopback0), destination 9. The keepalive is double-encapsulated, so the remote peer receives the keepalive, decapsulates it, and is ‘tricked’ into sending the response. Tried with service-loopback binded to physical interface but still tunnel is showing down down. 1 Route Port,The Maximum Transmit Unit is 1500 Internet Address is 100. KB ID 0000954 Dtd 09/06/14. device # show interface tunnel 10 Tunnel10 is up, line protocol is up Hardware is Tunnel Tunnel source 1. In this example you configure a unidirectional filter-based GRE IPv4 tunnel from Router PE1 to Router PE2, providing a logical path from IPv6 network C1 to IPv6 network C2. "tunnel mode ipsec [ipv4/ipv6]". 10 Tunnel destination is 1. X Tunnel mtu is set to 1100 Tunnel is an IP GRE TUNNEL Tunnel is Trusted Inter Tunnel Flooding is enabled Tunnel keepalive is enabled Tunnel keepalive interval is 10 seconds,. Re: tunnel up line protocol down « Reply #8 on: September 22, 2011, 12:04:36 PM » Yeah not all IOS image feature sets support the 6in4 tunneling needed to use a HE. This continues until the tunnel is terminated. 255 exit ! interface Tunnel 1 dynamic-cac 128 keepalive 10 3 tunnel source 192. Cisco Nexus Switch Basic CLI Commands I recently visited Perth Western Australia for a core switch upgrade project and it was cold and rainy during my stay there. Multiprotocol Label Switching ( MPLS) is a type of data-carrying technique for high-performance telecommunications networks. 9 Tunnel Subblocks: src-track:. Five of the six spokes work fine. A set of 5 GRE tunnels will be implemented connecting r1àr2, r2àr3, r3àr4, r4àr5, and r5àr1. Generic Routing Encapsulation (GRE) is a tunneling protocol that can encapsulate any network layer protocol (such as IPv6) into a virtual point-to-point tunnel over an IP network (such as an IPv4 network). And while the level of security PPTP provides has. ESP or encapsulated (e. Configure DMVPN Phase3 between R1, R2, and R3 as follows: Use R1 as the hub. The ability to mark an interface as down when the remote end of the link is not available is used in order to remove any routes (specifically static routes) in the routing table that use that interface as the outbound interface. The tunnel destination interface is flapping, which causes the tunnel to go up and down. Typically, GRE tunnel is encapsulated inside the IPSec tunnel and this model is called GRE over IPSec. The adjacency on the tunnel interface is termed a ԭid-chainՠthis it is now present in the middle of the graph/chain rather than its usual terminal location. GRE Tunnel 用默认路由建立时将出现down的情况。 Line protocol on Interface Tunnel0, changed state to up (Generic Routing Encapsulation):. X/24) Configure LAPTOP IP to be the same subnet IP as Hub Routers. This can lead to routing blackholes. It can carry almost any layer 3 protocol. I have two cisco routers with tunnels between them. The key benefits are the ability to forward another protocol down it and the ability to route through the tunnel transparent to all the hops it goes through. پس چنانچه در چند بازه زمانی، فرستنده مکانیزم keep-alive پاسخ را دریافت نکند، line protocol اینترفیس Tunnel خود را down می نماید. I have a GRE tunnel that is running between a Comware 5510HI and MSR954. 3 (Serial2/0/0), destination 0. 38 0x00000002 2nd. GRE is used to create a tunnel so that it appears as one link from source to destination. 0 Tunnel protocol/transport GRE/IP, key disabled. The actual encryption algorithm within the tunnel is negotiated when the ESP session starts up. Up/down – This implies that, even though the tunnel is administratively up, something causes the line protocol on the interface to be down. Figure 1-18 IPSec Encrypted Tunnel. In the Proxy-ID ACL, the "tunnel source" IP and the "tunnel destination" IP that was configured on. 1 YES manual up down. 254 Destination 172. 2, and two ZENs in two different data centers (216. This means that each tunnel endpoint does not keep any information about the state or availability of the remote tunnel endpoint. Administratively down/down - This implies that the interface has been. GRE: Use GRE encapsulation on the tunnel interface. Generic Routing Encapsulation (GRE) is a tunneling protocol developed by Cisco Systems that can encapsulate a wide variety of network layer protocols inside virtual point-to-point links over an Internet Protocol network. The created IP tunnel entity is also called the Citrix Cloud Connector tunnel entity. Attempt to ping the IP address of PCA from PCB. * causes havoc down the line (ip_local_out et. I am not sure if it is with the GRE or the IPSec tunnel. INFS 6760 – RMU C&IS. Tunnel 1 is up line protocol is down Description: Tunnel Interface Internet address is X. HUB1: crypto isakmp policy 100 encr 3des authentication pre-share group 2 crypto isakmp key ISAKMPKEY1 address 0. We're running EIGRP. RE: GRE Tunnel: Line Protocol Down? BuckWeet (IS/IT--Management) 14 Nov 08 21:40 Its because when you bring up the tunnel the static routes that you have for the tunnel interfaces kick in. در تونل GRE در صورتی که یکی از طرفین ارتباط تونل قطع شود، طرف مقابل قادر به تشخیص قطعی تونل و down کردن line protocol نیست و لذا ترافیک ها روی مسیر تونل ارسال می شود اما ترافیک تونل هیچگاه به مقصد نمی رسد. 1 Tunnel protocol/transport GRE/IP Key disabled, sequencing disabled Checksumming of packets disabled Tunnel TTL 255 Fast tunneling enabled Tunnel transmit bandwidth 8000 (kbps. A consequence of this is that the local tunnel end-point router does not have the ability to bring the line protocol of the GRE tunnel interface down if the remote end-point is unreachable. 2/24 Encapsulation is TUNNEL, loopback not set Tunnel source 10. We tested, and it worked. I started doing network security (with CCNA Security) back in 2012 and I'm now enjoying the traveling perks because of my network security skills. It can carry almost any layer 3 protocol. But I have one Router in NAT environment that it's ip address is private IP address and another outside Router is public IP address, so when I configure "keepalive" on tunnel interface, the tuneel interface would show "line protocol down" message directly.