[RE: [nsp] gre tunnel using loopback for source]

[Pete Templin]

OSPF provides the most specific reachability, and the default route points the same way as well.

I'm statically policy routing into the tunnels from a FastE subinterface, and following "normal" destination-based routing from the tunnel to the subinterface at the far end.

Pete Templin
IP Network Engineer
Tex-Link Communications
pete.templin at texlink.com
(210) 892-4183

-----Original Message-----
From: Joshua Sahala [mailto:joshua.ej.smith at usa.net]
Sent: Monday, June 02, 2003 5:31 PM
To: Pete Templin; Joshua Sahala; cisco-nsp at puck.nether.net
Subject: Re: [RE: [nsp] gre tunnel using loopback for source]

pete,

thanks for the reply - are you using static or dynamic routing for
underlying reachability? 

/joshua

"Pete Templin" <pete.templin at texlink.com> wrote:
> I've got ten tunnels in a full mesh between five sites, all using the
loopback as the source and the destination.
>
> On IOS 12.2(16), I did notice (but didn't investigate further; didn't have
an easy way to build a test network due to overlapping VLAN identifiers) that
the tunnel would show a status of up/up as soon as a valid route was created
to the destination, even if the far end router was non-existent.  Might have
been a random goof on my part; but might be more important in other
topologies.
>
> Pete Templin
> IP Network Engineer
> Tex-Link Communications
> pete.templin at texlink.com
> (210) 892-4183
>
> -----Original Message-----
> From: Joshua Sahala [mailto:joshua.ej.smith at usa.net]
> Sent: Monday, June 02, 2003 3:52 PM
> To: cisco-nsp at puck.nether.net
> Subject: [nsp] gre tunnel using loopback for source
>
> hello all,
>
> i was wondering if it is possible to get a gre tunnel to work using
> a loopback for the tunnel source.  i have three interfaces (traffic
> is moved from one to another by local preference) that could
> potentially be the active interface, so i am trying to get a tunnel
> that will stay up if i move the traffic off the interface.
> bgp will come up, and addresses in lan2 can ping my router, but not
> any devices in lan 1, and lan1 devices cannot ping the r2 loopback,
> or any lan2 devices
>
>
> lan1
>  |
> r1
>  |
> r2
>  |
> lan2
>
> r1 config:
> interface Tunnel17
>  description connected_to_test
>  ip unnumbered Loopback19
>  no ip directed-broadcast
>  ip mtu 1580
>  tunnel source 192.168.1.194
>  tunnel destination 10.10.1.42
>
> interface Loopback19
>  ip address 192.168.1.194 255.255.255.255
>  no ip redirects
>  no ip unreachables
>  no ip directed-broadcast
>  no ip proxy-arp
>
> router bgp 65056
> network 192.168.1.0 mask 255.255.255.0
> neigh 172.16.16.1 remote as 65145
>
> ip route 172.16.16.1 255.255.255.255 tun17
>
>
> r2 config
>
> interface Tunnel1
>  description connected_to_test
>  ip unnumbered Loopback9
>  no ip directed-broadcast
>  ip mtu 1580
>  tunnel source 10.10.1.42
>  tunnel destination 192.168.1.194
>
> interface Loopback9
>  ip address 172.16.16.1 255.255.255.255
>  no ip redirects
>  no ip unreachables
>  no ip directed-broadcast
>  no ip proxy-arp
>
> router bgp 65145
> network 172.16.16.0 255.255.255.0
> neigh 192.168.1.194 remote as 65056
>
> ip route 192.168.1.194 255.255.255.255 tun1
> ip route 192.168.1.19 255.255.255.255 fas1/1
>
> int fas1/1
> ip address 10.10.1.42 255.255.255.252
>
> thanks
>
> /joshua
>
>
> "Walk with me through the Universe,
>  And along the way see how all of us are Connected.
>  Feast the eyes of your Soul,
>  On the Love that abounds.
>  In all places at once, seemingly endless,
>  Like your own existence."
>      - Stephen Hawking -
>
>
>
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>



"Walk with me through the Universe,
 And along the way see how all of us are Connected.
 Feast the eyes of your Soul,
 On the Love that abounds.
 In all places at once, seemingly endless,
 Like your own existence."
     - Stephen Hawking -