[c-nsp] PoP's, Routing and GRE

[Mark Tohill]

We have the following scenario:

 

A newly installed DSL PoP.

 

| H1------S1----R1----ISP1

|    \    /\     /

|     \  /  \   /

|      \/    \ /

|      /\     \

|     /  \   / \

|    /    \ /   \

| H3----- S2----R2----ISP1

 

H1/2 are dual-homed hosts.

S1/2 are WS-2970G-24's.

R1/2 are 7204VXR's with NPE-G1's connecting to redundant links in
providers PoP.

 

 

We have a problem whereby we have 2 x /24's of fixed IP /32 users and
another /25 of same who were being announced via BGP (3 x Class C's) to
the old PoP. These users need to get transferred. We could announce the
two class C's from the new PoP but what about the /25? Whose going to
route a /25!!!??!! Keep in mind the second half of the /25 must remain
in original PoP.

 

We thought GRE tunneling might get this static traffic across to new PoP
without getting it bounced back to us via BGP. We set up tunnels on the
old PoP edge and on new PoP edge 7200's.

We then pointed the 2 /24's and /25 across tunnel. The tunnels stayed no
more that half a minute and then dropped.

 

I know it's not pretty but that's the way assignments have happened.
Have we any other options here to sort out these customers?

 

Any thoughts welcome.

 

Thanks.