question on bgp maximum-path

[Madhu-api]

Hi

Is there a specific way we can test bgp maximum-path feature?

I have configured the following

router bgp 3322
 no bgp fast-external-failover
 no bgp ebgp-requires-policy
 bgp bestpath as-path multipath-relax
 timers bgp 1 3
 neighbor 172.19.0.2 remote-as 2211
 neighbor 172.20.0.3 remote-as 4433
 !
 address-family ipv4 unicast
  network 172.19.0.0/24
  network 172.20.0.0/24
  maximum-paths 2
 exit-address-family
exit
!
end

ip route table received both the routes

B>* 11.11.11.0/24 [20/0] via 172.19.0.2, eth0, weight 1, 00:01:33
  *                      via 172.20.0.3, eth1, weight 1, 00:01:33

but kernel has only one route

root@4fe17651fcaf:/go/src/app# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.19.0.1      0.0.0.0         UG    0      0        0 eth0
11.11.11.0      172.19.0.2      255.255.255.0   UG    20     0        0 eth0
172.18.0.0      172.19.0.2      255.255.255.0   UG    20     0        0 eth0
172.19.0.0      0.0.0.0         255.255.255.0   U     0      0        0 eth0
172.20.0.0      0.0.0.0         255.255.255.0   U     0      0        0 eth1
172.21.0.0      172.19.0.2      255.255.255.0   UG    20     0        0 eth0
root@4fe17651fcaf:/go/src/app#

When i send ping traffic , it is sent via only one path (verified using tcpdump)
when I send iperf TCP traffic, iperf3 fails.

Any idea, if im missing any config?

4fe17651fcaf# show running-config
Building configuration...

Current configuration:
!
frr version 9.2-dev-my-manual-build
frr defaults traditional
hostname 4fe17651fcaf
no ipv6 forwarding
!
router bgp 3322
 no bgp fast-external-failover
 no bgp ebgp-requires-policy
 bgp bestpath as-path multipath-relax
 timers bgp 1 3
 neighbor 172.19.0.2 remote-as 2211
 neighbor 172.20.0.3 remote-as 4433
 !
 address-family ipv4 unicast
  network 172.19.0.0/24
  network 172.20.0.0/24
  maximum-paths 2
 exit-address-family
exit
!
end

4fe17651fcaf# sho vers
FRRouting 9.2-dev-my-manual-build (4fe17651fcaf) on Linux(5.4.0-167-generic).
Copyright 1996-2005 Kunihiro Ishiguro, et al.
configured with:
    '--prefix=/usr' '--localstatedir=/var/run/frr' '--sbindir=/usr/lib/frr' '--sysconfdir=/etc/frr' '--enable-sharpd' '--enable-multipath=64' '--enable-user=frr' '--enable-group=frr' '--enable-config-rollbacks' '--enable-vty-group=frrvty' '--enable-snmp=agentx' '--enable-scripting' '--with-pkg-extra-version=-my-manual-build'
4fe17651fcaf#

4fe17651fcaf# show ip bgp
BGP table version is 205, local router ID is 172.20.0.2, vrf id 0
Default local pref 100, local AS 3322
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
RPKI validation codes: V valid, I invalid, N Not found

    Network          Next Hop            Metric LocPrf Weight Path
 *= 11.11.11.0/24    172.20.0.3                             0 4433 1122 i
 *>                  172.19.0.2                             0 2211 1122 i
 *= 172.18.0.0/24    172.20.0.3                             0 4433 1122 i
 *>                  172.19.0.2                             0 2211 1122 i
 *> 172.19.0.0/24    0.0.0.0                  0         32768 i
 *> 172.20.0.0/24    0.0.0.0                  0         32768 i
 *= 172.21.0.0/24    172.20.0.3                             0 4433 1122 i
 *>                  172.19.0.2                             0 2211 1122 i

Displayed  5 routes and 8 total paths
4fe17651fcaf#

[ton31337]

Please use markdown formatting for the outputs, it's very tricky reading them unformatted properly.

[donaldsharp]

route -n does not show multipath

sharpd@eva ~/frr2 (zebra_final_shutdown_finally) [3]> route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.119.1   0.0.0.0         UG    100    0        0 enp13s0
4.5.6.7         192.168.119.1   255.255.255.255 UGH   20     0        0 enp13s0

Use ip route show

sharpd@eva ~/frr2 (zebra_final_shutdown_finally)> ip route show
default via 192.168.119.1 dev enp13s0 proto dhcp metric 100 
4.5.6.7 nhid 16 proto 196 metric 20 
	nexthop via 192.168.119.1 dev enp13s0 weight 1 
	nexthop via 192.168.119.2 dev enp13s0 weight 1 

the vtysh output:

vtysh -c "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, t - Table-Direct,
       > - selected route, * - FIB route, q - queued, r - rejected, b - backup
       t - trapped, o - offload failure

K>* 0.0.0.0/0 [0/100] via 192.168.119.1, enp13s0, 00:01:50
S>* 4.5.6.7/32 [1/0] via 192.168.119.1, enp13s0, weight 1, 00:01:33
  *                  via 192.168.119.2, enp13s0, weight 1, 00:01:33