BGP - Network subcommand

Daniel333Daniel333 Member Posts: 2,077 ■■■■■■□□□□
So I am setting up a basic BGP topology.

Weird thing, it doesn't work when I use the
#network 192.168.1.0 mask 255.255.255.0

but works fine when I do this
#network 192.168.1.0

Any idea why that might be? Shouldn't they mean the same thing?
-Daniel

Comments

  • mikej412mikej412 Member Posts: 10,086 ■■■■■■■■■■
    Daniel333 wrote: »
    Shouldn't they mean the same thing?

    It depends on what you mean by it didn't work and it did work.

    It's BGP -- so how it works depends on whether auto summary is enabled or not. Current versions of IOS disable auto summary by default -- so it's a good habit to get into using the mask keyword.
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  • chmorinchmorin Member Posts: 1,446 ■■■■■□□□□□
    mikej412 wrote: »
    It depends on what you mean by it didn't work and it did work.

    It's BGP -- so how it works depends on whether auto summary is enabled or not. Current versions of IOS disable auto summary by default -- so it's a good habit to get into using the mask keyword.

    I also believe the same rule could apply to other routing protocols as well like EIGRP. I remember it being banged into my head that once I first configure the protocol, to type in "no auto-summary" as my next command. Like you said I don't think this is needed in newer IOS versions.

    Unless you want auto summary, that is. Most don't now-a-days.
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  • Daniel333Daniel333 Member Posts: 2,077 ■■■■■■□□□□
    Turns out I just didn't wait long enough. Sorry, kinda embarrassed.
    -Daniel
  • Forsaken_GAForsaken_GA Member Posts: 4,024
    Daniel333 wrote: »
    Turns out I just didn't wait long enough. Sorry, kinda embarrassed.

    Yeah, BGP route propagation isn't instant like the IGP protocols, sometimes it takes a few for your routes to be announced
  • deth1kdeth1k Member Posts: 312
    This is down to BGP Scanner process which verifies next hop of every route in BGP RIB every 60 seconds. You can tune it down to 1 second but that could cause an instability in a live environment network.

    command: "bgp scan-time"

    HTH
  • NetwurkNetwurk Member Posts: 1,155 ■■■■■□□□□□
    For what it's worth, here's my lab's BGP config


    router bgp 65500
    no synchronization
    bgp log-neighbor-changes
    network 10.10.10.0 mask 255.255.255.0
    neighbor 192.168.55.5 remote-as 65501


    and

    router bgp 65501
    no synchronization
    bgp log-neighbor-changes
    network 172.16.7.0 mask 255.255.255.0
    neighbor 192.168.55.6 remote-as 65500


    Thanks to BGP I can now ping 10.10.10.x from 65501.

    From 65501, sh ip route shows

    sh ip route
    Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
    D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
    N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
    E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
    i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter are
    * - candidate default, U - per-user static route, o - ODR
    P - periodic downloaded static route
    (unnecessary output not shown)
    B 10.10.10.0/24 [20/0] via 192.168.55.6, 1w5d


    BGP is of course the EGP everyone uses nowadays. All the other protocols are IGP's.

    EGP (the protocol that BGP replaced) is the only other EGP that I know of other than BGP.

    I hope this helps D333, happy holidays to you and yours.

    :)
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