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<tt>Hi<br>
<br>
we've got a private AS with two uplinks to our ISP, and we've got
a number of subnets that we advertise. Now we got a new assignment
and it doesn't work as expected.<br>
<br>
Here is the situation:<br>
<br>
x.x.74.113<br>
x.x.74.114<br>
[DMZ1_box_1]<br>
||<br>
[DMZ1_GW] -- OSPF -- [GW_1] -- OSPF -- [GW_2] -- OSPF -- ...<br>
x.x.24.227<br>
| |<br>
BGP BGP<br>
| |<br>
ISP_rtr_1 ISP_rtr_2<br>
\ /<br>
ISP & Internet<br>
<br>
Now if I advertise the new subnet /29 (or up to /31) from DMZ1_GW
it gets propagated to both BGPs and the ISP correctly routes the
traffic to GW_1 as it's closer to the box.<br>
<br>
However if I advertise the IP/32 from DMZ1_GW then for some reason
the traffic is routed from Internet to GW_2 first. ISP confirmed
they accept up to /32 from us.<br>
<br>
This is the relevant output from GW_1:<br>
GW_1 ~ # birdc show route protocol ospf_eit</tt> <tt><tt>| grep
^x.x.74<br>
</tt>BIRD 1.3.8 ready.<br>
x.x.74.114/32 via 172.31.253.32 on tunVpnCust [ospf_eit 11:44] *
E2 (150/1/10000) [x.x.24.227]<br>
x.x.74.112/31 via 172.31.253.32 on tunVpnCust [ospf_eit 11:44] *
E2 (150/1/10000) [x.x.24.227]<br>
<br>
GW_1 ~ # birdc show route export bgp_isp</tt> <tt><tt>| grep
^x.x.74<br>
</tt>BIRD 1.3.8 ready.<br>
x.x.74.114/32 via 172.31.253.32 on ifDmz1 [ospf_eit 11:44] * E2
(150/1/10000) [x.x.24.227]<br>
x.x.74.112/31 via 172.31.253.32 on ifDmz1 [ospf_eit 11:44] * E2
(150/1/10000) [x.x.24.227]<br>
<br>
<br>
This is the relevant output from GW_2:<br>
GW_2 ~ # birdc show route protocol ospf_eit</tt><tt><tt> | grep
^x.x.74<br>
</tt>BIRD 1.3.8 ready.<br>
x.x.74.114/32 via 172.31.253.1 on tunO2Oorc4 [ospf_eit 11:44] * E2
(150/11/10000) [x.x.24.227]<br>
x.x.74.112/31 via 172.31.253.1 on tunO2Oorc4 [ospf_eit 11:44] * E2
(150/11/10000) [x.x.24.227]<br>
<br>
GW_2 ~ # birdc show route export bgp_isp | grep ^x.x.74<br>
BIRD 1.3.8 ready.<br>
x.x.74.114/32 via 172.31.253.1 on tunO2Oorc4 [ospf_eit 11:44] * E2
(150/11/10000) [x.x.24.227]<br>
x.x.74.112/31 via 172.31.253.1 on tunO2Oorc4 [ospf_eit 11:44] * E2
(150/11/10000) [x.x.24.227]<br>
<br>
As it is now a ping from outside to x.x.74.113 (that's advertised
as /31) goes to GW_1, which is correct and a ping to x.x.74.114
(that's advertised as /32) goes to GW_2, that's incorrect.<br>
<br>
How come? I can't see what am I doing wrong...?<br>
<br>
Any ideas?<br>
<br>
Thanks<br>
<br>
Michael<br>
</tt>
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