| 2015-06-04 20:35:48 |
amit surana |
description |
When interface static routes are provisioned and point to the VMIs of (regular) VMs, agent treats them as active/backup pair and reduces the priority of all but one route, thus not doing ECMP.
In the topology below, an interface static route is provisioned to destination network 1.0.0.0/8 pointing to the left interface of both VM1 and VM2. To being with, both those routes are advertised to the MX with equal local preference of 200 and multi path is setup. Upon sending traffic, the local pref of one of the routes is reduced to 100.
This might be related/similar to 1461787, but logging it to track this specific case of VMs with different IPs having interface static routes pointing to them.
|----VM1----P_VN1----|
cli_vrf----C_VN----| LR-------GW1------ser_vrf
|----VM2----P_VN2----|
C_VN:
root@csol2-node11:~# rt --dump 1 | grep 2.0.0.0
2.0.0.0/8 8 PT - 38 -
root@csol2-node11:~# nh --get 38
Id:38 Type:Composite Fmly: AF_INET Flags:Valid, Policy, Ecmp, Rid:0 Ref_cnt:2 Vrf:1
Sub NH(label): 15(25) 25(23)
P_VN1:
root@csol2-node11:~# rt --dump 2 | grep 1.0.0.0 | more
1.0.0.0/8 8 PT - 40 -
root@csol2-node11:~# nh --get 40
Id:40 Type:Composite Fmly: AF_INET Flags:Valid, Policy, Ecmp, Rid:0 Ref_cnt:2 Vrf:2
Sub NH(label): 15(30) 34(30)
MX:
root@cmbu-tasman# run show route table spi_cli.inet.0
spi_cli.inet.0: 7 destinations, 13 routes (7 active, 0 holddown, 0 hidden)
@ = Routing Use Only, # = Forwarding Use Only
+ = Active Route, - = Last Active, * = Both
2.0.0.0/8 @[BGP/170] 01:05:23, localpref 100, from 172.16.180.5
AS path: ?, validation-state: unverified
> via gr-2/1/0.32772, Push 23
[BGP/170] 01:05:23, localpref 100, from 172.16.180.5
AS path: ?, validation-state: unverified
> via gr-2/2/0.32771, Push 25
[BGP/170] 01:05:23, localpref 100, from 172.16.180.7
AS path: ?, validation-state: unverified
> via gr-2/1/0.32772, Push 23
[BGP/170] 01:05:23, localpref 100, from 172.16.180.7
AS path: ?, validation-state: unverified
> via gr-2/2/0.32771, Push 25
#[Multipath/255] 01:05:23, metric2 0
> via gr-2/1/0.32772, Push 23
via gr-2/2/0.32771, Push 25 |
When interface static routes are provisioned and point to the VMIs of (regular) VMs, agent treats them as active/backup pair and reduces the priority of all but one route, thus not doing ECMP.
In the topology below, an interface static route is provisioned to destination network 1.0.0.0/8 pointing to the left interface of both VM1 and VM2. To being with, both those routes are advertised to the MX with equal local preference of 200 and multi path is setup. Upon sending traffic, the local pref of one of the routes is reduced to 100.
This might be related/similar to 1461787, but logging it to track this specific case of VMs with different IPs having interface static routes pointing to them.
|----VM1----P_VN1----|
cli_vrf---C_VN----| LR---GW1---ser_vrf
|----VM2----P_VN2----|
C_VN:
root@csol2-node11:~# rt --dump 1 | grep 2.0.0.0
2.0.0.0/8 8 PT - 38 -
root@csol2-node11:~# nh --get 38
Id:38 Type:Composite Fmly: AF_INET Flags:Valid, Policy, Ecmp, Rid:0 Ref_cnt:2 Vrf:1
Sub NH(label): 15(25) 25(23)
P_VN1:
root@csol2-node11:~# rt --dump 2 | grep 1.0.0.0 | more
1.0.0.0/8 8 PT - 40 -
root@csol2-node11:~# nh --get 40
Id:40 Type:Composite Fmly: AF_INET Flags:Valid, Policy, Ecmp, Rid:0 Ref_cnt:2 Vrf:2
Sub NH(label): 15(30) 34(30)
MX:
root@cmbu-tasman# run show route table spi_cli.inet.0
spi_cli.inet.0: 7 destinations, 13 routes (7 active, 0 holddown, 0 hidden)
@ = Routing Use Only, # = Forwarding Use Only
+ = Active Route, - = Last Active, * = Both
2.0.0.0/8 @[BGP/170] 01:05:23, localpref 100, from 172.16.180.5
AS path: ?, validation-state: unverified
> via gr-2/1/0.32772, Push 23
[BGP/170] 01:05:23, localpref 100, from 172.16.180.5
AS path: ?, validation-state: unverified
> via gr-2/2/0.32771, Push 25
[BGP/170] 01:05:23, localpref 100, from 172.16.180.7
AS path: ?, validation-state: unverified
> via gr-2/1/0.32772, Push 23
[BGP/170] 01:05:23, localpref 100, from 172.16.180.7
AS path: ?, validation-state: unverified
> via gr-2/2/0.32771, Push 25
#[Multipath/255] 01:05:23, metric2 0
> via gr-2/1/0.32772, Push 23
via gr-2/2/0.32771, Push 25 |
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