Dynamic Reconfiguration

This scenario shows how to create a GRE tunnel and perform some dynamic configuration changes on it.

../../../../_images/gre1.svg

Test Dynamic Changes On GRE Tunnel

Description

A tunnel interface is configured in each node and the ‘Ping’ command is used to check network connectivity (ICMP protocol). Afterwards, NHRP configuration is replaced by a fixed remote network and ICMP connectivy is checked again. Finally, initial configuration is restored to ensure NHRP is working fine.

Scenario

Step 1: Set the following configuration in DUT0:

set interfaces eth0.100 address 192.168.100.10/24
set interfaces tunnel tun0 address 100.0.0.1/32
set interfaces tunnel tun0 encapsulation gre
set interfaces tunnel tun0 local-address 192.168.100.10
set interfaces tunnel tun0 nhrp
set protocols static route 0.0.0.0/0 next-hop 192.168.100.20

Step 2: Set the following configuration in DUT1:

set interfaces eth0.200 address 192.168.200.10/24
set interfaces tunnel tun0 address 200.0.0.1/32
set interfaces tunnel tun0 encapsulation gre
set interfaces tunnel tun0 local-address 192.168.200.10
set interfaces tunnel tun0 nhrp nhs 100.0.0.1 nbma 192.168.100.10
set protocols static route 0.0.0.0/0 next-hop 192.168.200.20

Step 3: Set the following configuration in DUT2:

set interfaces eth0.100 address 192.168.100.20/24
set interfaces eth1.200 address 192.168.200.20/24

Step 4: Ping IP address 192.168.200.20 from DUT0:

admin@DUT0$ ping 192.168.200.20 count 1 size 56 timeout 1
Show output
PING 192.168.200.20 (192.168.200.20) 56(84) bytes of data.
64 bytes from 192.168.200.20: icmp_seq=1 ttl=64 time=0.496 ms

--- 192.168.200.20 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.496/0.496/0.496/0.000 ms

Step 5: Run command protocols ip show nhrp at DUT0 and check if output matches the following regular expressions:

tun0\s+dynamic\s+200\.0\.0\.1
Show output
Iface      Type     Protocol         NBMA             Claimed NBMA     Expires(s)   Flags  Identity
tun0       local    100.0.0.1        192.168.100.10   192.168.100.10   -                   -
tun0       dynamic  200.0.0.1        192.168.200.10   192.168.200.10   7199         UTA

Step 6: Ping IP address 200.0.0.1 from DUT0:

admin@DUT0$ ping 200.0.0.1 count 1 size 56 timeout 1
Show output
PING 200.0.0.1 (200.0.0.1) 56(84) bytes of data.
64 bytes from 200.0.0.1: icmp_seq=1 ttl=64 time=0.477 ms

--- 200.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.477/0.477/0.477/0.000 ms

Step 7: Set the following configuration in DUT0:

del interfaces tunnel tun0 nhrp
set interfaces tunnel tun0 remote-ip 192.168.200.10
set protocols static route 200.0.0.1/32 interface tun0

Step 8: Set the following configuration in DUT1:

del interfaces tunnel tun0 nhrp
set interfaces tunnel tun0 remote-ip 192.168.100.10
set protocols static route 100.0.0.1/32 interface tun0

Step 9: Ping IP address 200.0.0.1 from DUT0:

admin@DUT0$ ping 200.0.0.1 count 1 size 56 timeout 1
Show output
PING 200.0.0.1 (200.0.0.1) 56(84) bytes of data.
64 bytes from 200.0.0.1: icmp_seq=1 ttl=64 time=0.580 ms

--- 200.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.580/0.580/0.580/0.000 ms

Step 10: Set the following configuration in DUT0:

del protocols static route 200.0.0.1/32
del interfaces tunnel tun0 remote-ip
set interfaces tunnel tun0 nhrp

Step 11: Set the following configuration in DUT1:

del protocols static route 100.0.0.1/32
del interfaces tunnel tun0 remote-ip
set interfaces tunnel tun0 nhrp nhs 100.0.0.1 nbma 192.168.100.10

Step 12: Run command protocols ip show nhrp at DUT0 and check if output matches the following regular expressions:

tun0\s+dynamic\s+200\.0\.0\.1
Show output
Iface      Type     Protocol         NBMA             Claimed NBMA     Expires(s)   Flags  Identity
tun0       local    100.0.0.1        192.168.100.10   192.168.100.10   -                   -
tun0       dynamic  200.0.0.1        192.168.200.10   192.168.200.10   7198         UTA

Step 13: Ping IP address 200.0.0.1 from DUT0:

admin@DUT0$ ping 200.0.0.1 count 1 size 56 timeout 1
Show output
PING 200.0.0.1 (200.0.0.1) 56(84) bytes of data.
64 bytes from 200.0.0.1: icmp_seq=1 ttl=64 time=0.552 ms

--- 200.0.0.1 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.552/0.552/0.552/0.000 ms