[FROG] BGP: /32 network cannot be advertised unless "no bgp network import-check" is present
Amol Lad
Amol.Lad at 4rf.com
Mon Sep 28 12:17:17 UTC 2020
Thanks Donald, your patch fixes the issue (both ipv4 and ipv6).
-----Original Message-----
From: Donald Sharp <sharpd at cumulusnetworks.com>
Sent: Monday, 28 September 2020 5:13 PM
To: Amol Lad <Amol.Lad at 4rf.com>
Cc: frog at lists.frrouting.org
Subject: Re: [FROG] BGP: /32 network cannot be advertised unless "no bgp network import-check" is present
Amol -
Please check and see if this commit fixes your issue:
commit e8442016a84d27c22ec1d9c8915ff7192277f680 (origin/pr/7182, donald/bgp_static_32s, bgp_static_32s)
Author: Donald Sharp <sharpd at nvidia.com>
Date: Fri Sep 25 09:45:24 2020 -0400
bgpd: Allow bgp static routes to use /32's
If you are including a network statement of a /32
then the current bgp martian checks will match the /32
together.
Problem:
!
router bgp 3235
neighbor 192.168.161.2 remote-as external
neighbor 192.168.161.131 remote-as external
!
address-family ipv4 unicast
network 10.10.3.11/32
network 192.168.161.0/24
no neighbor 192.168.161.2 activate
neighbor 192.168.161.2 route-map BLUE in
exit-address-family
!
eva# show bgp ipv4 uni
BGP table version is 1, local router ID is 10.10.3.11, vrf id 0
Default local pref 100, local AS 3235
Status codes: s suppressed, d damped, h history, * valid, > best, = multipath,
i internal, r RIB-failure, S Stale, R Removed
Nexthop codes: @NNN nexthop's vrf id, < announce-nh-self
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
10.10.3.11/32 0.0.0.0(eva) 0 32768 i
*> 192.168.161.0/24 0.0.0.0(eva) 0 32768 i
Displayed 2 routes and 2 total paths
eva# show bgp import-check-table
Current BGP import check cache:
192.168.161.0 valid [IGP metric 0], #paths 1
if enp39s0
Last update: Fri Sep 25 08:00:42 2020
10.10.3.11 valid [IGP metric 0], #paths 1
if lo
Last update: Fri Sep 25 08:00:42 2020
eva# show bgp ipv4 uni summ
BGP router identifier 10.10.3.11, local AS number 3235 vrf-id 0
BGP table version 1
RIB entries 3, using 576 bytes of memory
Peers 1, using 21 KiB of memory
Neighbor V AS MsgRcvd MsgSent TblVer
InQ OutQ Up/Down State/PfxRcd PfxSnt
janelle(192.168.161.131) 4 60000 69 70 0
0 0 00:03:21 0 1
Total number of neighbors 1
When we are deciding that a nexthop is valid there is not much point in checking
that a static route has a martian nexthop or not, since we self derived it already.
Signed-off-by: Donald Sharp <sharpd at nvidia.com>
donald
On Mon, Sep 28, 2020 at 6:46 AM Amol Lad <Amol.Lad at 4rf.com> wrote:
>
> Hi,
>
> I've configured a dummy interface (in Linux) with IP Address 1.1.1.1/32 and advertising it in BGP. However, this network is not getting advertised unless I also give "no bgp network import-check" command. Please see below for more details and advise what could be going wrong or I'm missing some other configuration.
>
> (Same is true with IPv6 address with /128 prefix - this also cannot be
> advertised unless no import-check is given even though the address
> present in IPv6 routing table)
>
> Thanks
> Amol
>
> Current configuration:
> !
> frr version 7.4
> frr defaults traditional
> hostname FRR
> log syslog
> !
> router bgp 1
> no bgp ebgp-requires-policy
> neighbor 10.10.10.2 remote-as 2
> !
> address-family ipv4 unicast
> network 1.1.1.1/32
> exit-address-family
> !
> line vty
> !
> end
>
> ====
>
> FRR(config-router)# do show ip route
> Codes: K - kernel route, C - connected, S - static, R - RIP,
> O - OSPF, I - IS-IS, B - BGP, E - EIGRP, N - NHRP,
> T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> F - PBR, f - OpenFabric,
> > - selected route, * - FIB route, q - queued route, r -
> rejected route
>
> K * 1.1.1.1/32 [0/10] is directly connected, loop0, 00:54:33
> C>* 1.1.1.1/32 is directly connected, loop0, 00:54:33
>
> ===
>
> [ As you can see "*>" is missing before 1.1.1.1/32. However, If I give
> "no bgp network import-check" then *> comes here and network is
> advertised to neighbor]
>
> FRR(config-router)# do show bgp ipv4 unicast BGP table version is 2,
> local router ID is 172.17.1.106, vrf id 0 Default local pref 100,
> local AS 64512 Status codes: s suppressed, d damped, h history, *
> valid, > best, = multipath,
> i internal, r RIB-failure, S Stale, R Removed Nexthop
> codes: @NNN nexthop's vrf id, < announce-nh-self Origin codes: i -
> IGP, e - EGP, ? - incomplete
>
> Network Next Hop Metric LocPrf Weight Path
> 1.1.1.1/32 0.0.0.0 0 32768 i
>
> Displayed 1 routes and 1 total paths
>
> ===
>
> root at FRR:/# ip addr show loop0
> 6: loop0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 1000
> link/ether 52:db:5f:99:52:d4 brd ff:ff:ff:ff:ff:ff
> inet 1.1.1.1/32 brd 255.255.255.255 scope global loop0
> valid_lft forever preferred_lft forever
> inet6 fe80::50db:5fff:fe99:52d4/64 scope link
> valid_lft forever preferred_lft forever
>
> ===
>
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