I have 3 Cisco 3845 Border routers running BGP. I have a
separate ISP for each Router. I am nat'ing on each router for our mail server on port
443. When I peer the 3 routers together I start getting smtp errors from our mail server
and users from the outside cannot get their email from Exchange server. To keep mail working I have put a
local preference of 500 for BGP on the first border router that makes it the preferred route. This is also the
original router with original ISP.
We have updated the MX DNS entries for our mail server to include the following entries for
our mail server. I replaced the real domain name and IP address.
Type Domain Name IP Address TTL
A mail.name.com 184.108.40.206 2 hrs
A mail.name.com 220.127.116.11 2 hrs
A mail.name.com 18.104.22.168 2 hrs
Can you let me know what I am missing in order to keep my mail server working or if you
need to see my BGP configurations.
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