This section describes the show commands that display the GRE tunnels configuration, the link status of the GRE tunnels, and the routes that use GRE tunnels.
To display GRE tunneling Information, use the following commands:
- show ip interface
- show ip route
- show ip interface tunnel
- show ip tunnel traffic
- show interface tunnel
- show statistics tunnel
The following shows an example output of the show ip interface command, which includes information about GRE tunnels.
device# show ip interfaceInterface IP-Address OK? Method Status Protocol VRF Tunnel 1 101.1.1.1 YES NVRAM up up red Tunnel 3 89.1.1.1 YES NVRAM up up default-vrf
For field definitions, refer to the FastIron Command Reference.
Syntax: show ip interface
The show ip route command displays routes that are pointing to a GRE tunnel as shown in the following example.
device# show ip routeTotal number of IP routes: 3, avail: 79996 (out of max 80000)B:BGP D:Connected R:RIP S:Static O:OSPF *:Candidate default Destination NetMask Gateway Port Cost Type1 10.1.1.0 255.255.255.0 0.0.0.0 7 1 D2 10.1.2.0 255.255.255.0 10.1.1.3 7 1 S3 10.34.3.0 255.255.255.0 0.0.0.0 tn3 1 D
For field definitions, refer to FastIron Command Reference.
Syntax: show ip route
The show ip interface tunnel command displays the link status and IP address configuration for an IP tunnel interface as shown in the following example.
device# show ip interface tunnel 64Interface Tunnel 64 port enabled port state: UP ip address: 223.224.64.0/31 Port belongs to VRF: default-vrf encapsulation: GRE, mtu: 1476, metric: 1 directed-broadcast-forwarding: disabled proxy-arp: disabled ip arp-age: 10 minutes No Helper Addresses are configured. No inbound ip access-list is set No outgoing ip access-list is set Syntax: show ip interface tunnel [ tunnel-ID ]
The tunnel-ID variable is a valid tunnel number between 1 and 72.
The show interface tunnel command displays the GRE tunnel configuration and the pmtd aging timer information.
device# show interface tunnel 10Tunnel10 is up, line protocol is up Hardware is Tunnel Tunnel source 1.1.41.10 Tunnel destination is 1.1.14.10 Tunnel mode gre ip Port name is GRE_10_to_VR1_on_ICX_STACK Internet address is 223.223.1.1/31, MTU 1476 bytes, encapsulation GRE Keepalive is not Enabled Path MTU Discovery: Enabled, MTU is 1428 bytes, age-timer: 10 minutes Path MTU will expire in 0 minutes 50 secs Syntax: show interface tunnel [ tunnel-ID ]
| Field | Definition |
|---|---|
| Hardware is Tunnel | The interface is a tunnel interface. |
| Tunnel source | The source address for the tunnel. |
| Tunnel destination | The destination address for the tunnel. |
| Tunnel mode | The tunnel mode. The gre specifies that the tunnel will use GRE encapsulation (IP protocol 47). |
| Port name | The port name (if applicable). |
| Internet address | The internet address. |
| MTU | The configured path maximum transmission unit. |
| encapsulation GRE | GRE encapsulation is enabled on the port. |
| Keepalive | Indicates whether or not GRE link keepalive is enabled. |
| Path MTU Discovery | Indicates whether or not PMTUD is enabled. If PMTUD is enabled, the MTU value is also displayed. |
| Path MTU | The PMTU that is dynamically learned. |
| Age-timer | Indicates the pmtd aging timer configuration in minutes.The default is 10. The range is from 10 - 30. |
| Path MTU will expire | Indicates the time after which the learned PMTU expires. This line is displayed only when a PMTU is dynamically learned. |
The show ip tunnel traffic command displays the link status of the tunnel and the number of keepalive packets received and sent on the tunnel.
device# show ip tunnel trafficIP GRE Tunnels Tunnel Status Packet Received Packet Sent KA recv KA sent 1 up/up 362 0 362 362 3 up/up 0 0 0 0 10 down/down 0 0 0 0 Syntax: show ip tunnel traffic
The show statistics tunnel command displays GRE tunnel statistics for a specific tunnel ID number. The following shows an example output for tunnel ID 1.
device(config-tnif-10)# show statistics tunnel 1IP GRE Tunnels Tunnel Status Packet Received Packet Sent KA recv KA sent 1 up/up 87120 43943 43208 43855 RFC 2784 supports GRE tunnel ports. The show statistics tunnel command output now includes information from the hardware counters for each tunnel. For example:
IP GRE Tunnel 1 HW Counters: InOctets 0 OutOctets 0 InPkts 0 OutPkts 0
Syntax: show statistics tunnel [ tunnel-ID ]
The tunnel-ID variable specifies the tunnel ID number.
| Field | Description |
|---|---|
| Tunnel Status | Indicates whether the tunnel is up or down. Possible values are:
|
| Packet Received | The number of packets received on the tunnel since it was last cleared by the administrator. |
| Packet Sent | The number of packets sent on the tunnel since it was last cleared by the administrator. |
| KA recv | The number of keepalive packets received on the tunnel since it was last cleared by the administrator. |
| KA sent | The number of keepalive packets sent on the tunnel since it was last cleared by the administrator. |
