SrikantRajeev
asked on
How to configure GRE tunnel between 2 Cisco Routers
I have two routers connected back to back. I am running OSPF between them.
I would like to know how to configure GRE tunnel between these 2 routers.
I would like to know how to configure GRE tunnel between these 2 routers.
Please show us botth routers config
Here's the basic idea:
And a link:
http://www.expertsupport.net/en/US/tech/tk86/tk89/technologies_configuration_example09186a008011520d.shtml
And a link:
http://www.expertsupport.net/en/US/tech/tk86/tk89/technologies_configuration_example09186a008011520d.shtml
Router 1:
interface tunnel 0
ip address 192.168.1.1 255.255.255.252
tunnel source fa0/0
tunnel destination 12.1.2.3
Router 2:
interface tunnel 0
ip address 192.168.1.2 255.255.255.252
tunnel source fa0/0
tunnel destination 160.160.1.19
ASKER
the link is not opening.
Just specifying source & destination IP will established the GRE tunnel
Just specifying source & destination IP will established the GRE tunnel
Yes. You would need to put the network command for the GRE interface's network address in the OSPF configuration to make OSPF work on the interface however.
>the link is not opening.
Works fine for me.
>Just specifying source & destination IP will established the GRE tunnel
On each router, correct.
Works fine for me.
>Just specifying source & destination IP will established the GRE tunnel
On each router, correct.
Please provide us:
sh ip int brief
sh ip route
sh ip mtu..
Don config is good, if it isn't working you must to use lower MTU on GRE tunnel interface, becouse GRE has 24 byte overhead, so you need this on tunnel interfaces:
int tun x
ip mtu 1476
and also on fasteth interfaces
int tun x
ip mtu 1476
ip tcp adjust-mss 1428
sh ip int brief
sh ip route
sh ip mtu..
Don config is good, if it isn't working you must to use lower MTU on GRE tunnel interface, becouse GRE has 24 byte overhead, so you need this on tunnel interfaces:
int tun x
ip mtu 1476
and also on fasteth interfaces
int tun x
ip mtu 1476
ip tcp adjust-mss 1428
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ASKER
MY GRE tunnel is working fine by just specifying the source & destination tunnel.
Let me know if any one has configured IPSec tunnel between Cisco Router & NEC IX router.
If any one has sample configuration to configure IPSec tunnel between Cisco router & NEC IX router please share the same with me
Let me know if any one has configured IPSec tunnel between Cisco Router & NEC IX router.
If any one has sample configuration to configure IPSec tunnel between Cisco router & NEC IX router please share the same with me
You should open a new question for this.