I hope I am posting this in the right spot. I can have an issue that I cannot tell if it is an EVE-NG thing or a personal lab configuration issue.
I have a prefix redistributed from BGP into my OSPF. Traffic for this destination is not being forwarded in an ECMP behavior like I would expect in a real setting. But in my troubleshooting I can see no reason why the traffic prefers to route on one side only.
Here is the topology. We will be looking at routes from the CGW router, which is the default gateway for my linux hosts.
My destination is 10.100.0.50 from a linux host. MTR shows the path it takes.
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My traceroute [v0.86]
ubuntu (0.0.0.0) Fri Feb 18 19:47:50 2022
Keys: Help Display mode Restart statistics Order of fields quit
Packets Pings
Host Loss% Snt Last Avg Best Wrst StDev
1. 172.16.100.1 0.0% 108 1.4 1.4 1.2 8.0 0.6
2. 172.16.201.5 0.0% 107 2.1 2.1 1.7 3.6 0.2
3. 192.168.100.5 0.0% 107 3.7 4.2 3.1 6.7 0.5
4. 10.100.0.50 0.0% 107 6.9 6.0 4.7 11.9 0.9
Here is the route information in the CGW device
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cgw#show ip route 10.100.0.50
Routing entry for 10.100.0.0/19
Known via "ospf 1", distance 110, metric 1
Tag 65001, type extern 2, forward metric 1
Last update from 172.16.201.1 on GigabitEthernet0/0, 00:22:33 ago
Routing Descriptor Blocks:
* 172.16.201.5, from 172.16.255.2, 00:22:33 ago, via GigabitEthernet0/1
Route metric is 1, traffic share count is 1
Route tag 65001
172.16.201.1, from 172.16.255.1, 00:22:33 ago, via GigabitEthernet0/0
Route metric is 1, traffic share count is 1
Route tag 65001
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cgw#show ip route 10.100.0.50
cgw#show ip ospf database external 10.100.0.0
OSPF Router with ID (172.16.255.3) (Process ID 1)
Type-5 AS External Link States
LS age: 1610
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 10.100.0.0 (External Network Number )
Advertising Router: 172.16.255.1
LS Seq Number: 80000001
Checksum: 0xEB0
Length: 36
Network Mask: /19
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 1
Forward Address: 0.0.0.0
External Route Tag: 65001
LS age: 1628
Options: (No TOS-capability, DC, Upward)
LS Type: AS External Link
Link State ID: 10.100.0.0 (External Network Number )
Advertising Router: 172.16.255.2
LS Seq Number: 80000001
Checksum: 0x8B5
Length: 36
Network Mask: /19
Metric Type: 2 (Larger than any link state path)
MTID: 0
Metric: 1
Forward Address: 0.0.0.0
External Route Tag: 65001
If I shut down my BGP peer on my BR2, traffic instantly fails over to the other side with 0 packet loss. So I know the other side works. Likewise if I shutdown BR2 all together traffic still moves across BR1. So the path works and I do not believe it is underlying eve network issue but I would not expect to see this behavior on a live device. I suppose its possible it could be an IOS bug?
I Know I've gotten ECMP to work in eve in the past so I am pretty confused by this one.