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AlfredT
AlfredT
Visitor III
January 31, 2022
Solved

Advertising BGP routes

  • January 31, 2022
  • 2 replies
  • 35117 views

Hi all, I'm trying to advertise some prefixes to my ISP using BGP but don't see any messages originating from the Fortigate to the ISP.

 

The ranges are in my routing table either as a static route or connected range. I've been following a few examples from the documentation but always end up with:

 

 

fg01 (root) # get router info bgp neighbors 162.57.210.17 advertised-routes % No prefix for neighbor 162.57.210.17

 

 

Current configuration is as follows:

 

 

config router prefix-list     edit "all_prefixes"         config rule             edit 1                 set prefix 78.121.89.0 255.255.255.0                 unset ge                 unset le             next             edit 2                 set prefix 78.121.88.128 255.255.255.192                 unset ge                 unset le             next         end     next end  config router route-map     edit "Filter_route"         config rule             edit 1                 set match-ip-address "all_prefixes"                 unset set-ip-nexthop                 unset set-ip6-nexthop                 unset set-ip6-nexthop-local                 unset set-originator-id             next         end     next end  config router bgp     set as 64761     set router-id 162.57.210.18     set ebgp-multipath enable     set graceful-restart enable     config neighbor         edit "162.57.210.17"             set prefix-list-out "all_prefixes"             set remote-as 1518         next     end     config network         edit 1             set prefix 78.121.89.0 255.255.255.0         next         edit 2             set prefix 78.121.88.128 255.255.255.192         next     end     config redistribute "connected"         set status enable     end     config redistribute "rip"     end     config redistribute "ospf"     end     config redistribute "static"         set status enable         set route-map "Filter_route"     end     config redistribute "isis"     end     config redistribute6 "connected"     end     config redistribute6 "rip"     end     config redistribute6 "ospf"     end     config redistribute6 "static"     end     config redistribute6 "isis"     end end

 

 

Any suggestions would be very much appreciated.

Best answer by akristof

Hello,

 

First, you don't need to filter routes under "redistribute static" as you are filtering them on neighbor level. But that's just cosmetic.

To your problem. Start from the beginning:

- Remove any filter and see if you are sending prefixes to the neighbor.

- Then verify that the prefix-list used for filtering is matching exactly the prefix+mask that you have in your routing-table.

- After every change you will do, soft-clear the BGP sesssion:
exec router clear bgp all soft

 

If you will have the same problem after you will prefix-list, you can enable BGP debug, hard clear BGP and see what FGT is doing with routes:

diag ip router bgp all en

diag ip router bgp nsm enable

diag ip router bgp level info

diag debug en

2 replies

akristof
Staff
akristofAnswer
Staff
January 31, 2022

Hello,

 

First, you don't need to filter routes under "redistribute static" as you are filtering them on neighbor level. But that's just cosmetic.

To your problem. Start from the beginning:

- Remove any filter and see if you are sending prefixes to the neighbor.

- Then verify that the prefix-list used for filtering is matching exactly the prefix+mask that you have in your routing-table.

- After every change you will do, soft-clear the BGP sesssion:
exec router clear bgp all soft

 

If you will have the same problem after you will prefix-list, you can enable BGP debug, hard clear BGP and see what FGT is doing with routes:

diag ip router bgp all en

diag ip router bgp nsm enable

diag ip router bgp level info

diag debug en

    AlfredT
    AlfredTAuthor
    Visitor III
    February 1, 2022

    Thank you very much. Removed the route route-map and learned via debugging that upstream required an MD5 password. Quite new to Fortigate and it's great to find an active community forum. 

    abelio
    SuperUser
    abelio
    SuperUser
    January 31, 2022

    Hello,
    to advertise a prefix, it must be active in the routing table as exactly was defined under 'config network'

    If you want advertise the prefix without take in consideration above comment, add:

    config router bgp
       ...
       set network-import-check disable
      ...
    end


    And, as Adrian pointed above, try to avoid redistribute static; could be a headache in the future.

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