Re: [linux-vrf-core] Using the same IP address for different vrf

[James R. L. <jl...@mi...>]

Hmmm.  very interesting.  My guess is that the route cache isn't keeping
VRF entries seperate.  If so it's definitly a bug.  To verify look in
/proc/net/rt_cache* and see what the entry look like for the dest your ping=
ing.


On Fri, Jul 22, 2005 at 12:26:20PM +0800, Affandi Indraji wrote:
> Hi all,
>=20
> I experience something strange if I configure different interface
> using the same IP address (on different VRF)
>=20
> ip addr
> 27: eth1.223: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue vrf 23
>     link/ether 00:02:55:7b:20:75 brd ff:ff:ff:ff:ff:ff
>     inet 10.11.3.2/24 scope global eth1.223
> 28: eth1.224: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue vrf 24
>     link/ether 00:02:55:7b:20:75 brd ff:ff:ff:ff:ff:ff
>     inet 10.11.3.2/24 scope global eth1.224
>=20
> ip route
> 10.11.3.0/24 dev eth1.223  proto kernel  scope link  src 10.11.3.2  vrf 23
> default via 10.11.3.1 dev eth1.223  vrf 23
> 10.11.3.0/24 dev eth1.224  proto kernel  scope link  src 10.11.3.2  vrf 24
> default via 10.11.3.1 dev eth1.224  vrf 24
> -----------------------------------------------
> test# chvrf 24 ping 10.11.3.1
> PING 10.11.3.1 (10.11.3.1) 56(84) bytes of data.
> 64 bytes from 10.11.3.1: icmp_seq=3D1 ttl=3D255 time=3D1.04 ms
> 64 bytes from 10.11.3.1: icmp_seq=3D2 ttl=3D255 time=3D0.387 ms
> 64 bytes from 10.11.3.1: icmp_seq=3D3 ttl=3D255 time=3D0.503 ms
>=20
> test# chvrf 23 ping 10.11.3.1
> PING 10.11.3.1 (10.11.3.1) 56(84) bytes of data.
> --- 10.11.3.1 ping statistics ---
> 7 packets transmitted, 0 received, 100% packet loss, time 5999ms
> ------------------------------------------
> as you can see, I can ping vrf 24 but not vrf 23. BUT, if I wait for a
> while I can ping vrf 23 but not vrf 24. (see below)
> ------------------------------------------
> test# chvrf 23 ping 10.11.3.1
> PING 10.11.3.1 (10.11.3.1) 56(84) bytes of data.
> 64 bytes from 10.11.3.1: icmp_seq=3D1 ttl=3D255 time=3D0.811 ms
> 64 bytes from 10.11.3.1: icmp_seq=3D2 ttl=3D255 time=3D0.369 ms
> 64 bytes from 10.11.3.1: icmp_seq=3D3 ttl=3D255 time=3D0.359 ms
>=20
> test# chvrf 24 ping 10.11.3.1
> PING 10.11.3.1 (10.11.3.1) 56(84) bytes of data.
>=20
> --- 10.11.3.1 ping statistics ---
> 2 packets transmitted, 0 received, 100% packet loss, time 999ms
> ---------------------
>=20
> Is there any limitation that we can't use the same IP address for
> different vrf? The reason I want to try it is to support the MPLS,
> using the same IP address for different VRF.
>=20
> /affandi
>=20
>=20
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--=20
James R. Leu
jl...@mi...