topic Re: [5900] management port : layer 2 and routing table in Comware Based

[5900] management port : layer 2 and routing table

fabbb — Wed, 21 Nov 2018 22:40:30 GMT

Hello all
I have 2 questions about how 5900 handles the management port

With the following setup ;

On the routeur the 2 ports connecting the 5900 are in the same vlan (let's say vlan 1).
On the 5900 traffic port (let's say port 1) is an access port bound to vlan 1.
The management port is of course not bound to any vlan (it can't be)
Management port and vlan-interface1 have an address in the same subnet as the router, which is the defaut gateway.

interface M-GigabitEthernet 0/0/0
ip address 172.16.0.20 24

vlan 1
name oam
interface vlan-interface1
ip address 172.16.0.10 24

ip route-static 0.0.0.0 0 172.16.0.254 permanent

1/ Will I have a L2 loop ?
I do not think so, because I believe vlan 1 is not extended to the management port.
But I"m not so sure about management port...

2/ How routing works with the management port ?
Let's say we want to ssh the 5900 on the out-of-band management : ssh 172.16.0.20
The request comes from .254 to the management port.
Will the answer leave the 5900 by the management port, because this is the way management port works : it always uses the same port used for entry ?
Or by the traffic port, because the 5900 will use the routing table ?
In the second case, the routing would be asymetric, but this would not be an issue really.

I know the best pratice would be to have another vlan and another subnet for the management port, but if this simple setup is OK it would be preferable in my case for some reason.

Thanks for your adivce !

Re: [5900] management port : layer 2 and routing table

parnassus — Thu, 22 Nov 2018 00:56:03 GMT

Management port (OoBM) normally doesn't share data plane with switched ports...so it's like another separated (single port) switch you're connecting to on the very same HPE FlexNetwork 5900 chassis...also there shouldn't be any route leaking between switch ports and OoBM management port...basically you should look at them like two separated switching environments.

Re: [5900] management port : layer 2 and routing table

fabbb — Thu, 22 Nov 2018 15:21:24 GMT

Thnaks Parnassus,

so I conclude from what you say, my setup would be fine then, no L2 loop, and separate routing table !

Now I understand I need to configure the routing specific to the mgmt port : actually, just a default route.

Is that correct ?

As I already have a default route (for the switched ports), how can I specify another default route specific for the mgmt port ?

Binding the mgmt port IP address to a specific vrf ('vpn-instance') ? Or does the mgmt port belongs to a special vrf by default ? Didn't find documentation about that ...

Thanks !

Re: [5900] management port : layer 2 and routing table

parnassus — Thu, 22 Nov 2018 20:21:15 GMT

Management (OoBM) port shouldn't support routing as happens to VLAN interface(s) on user data plane (I mean: you can't add a static route other than having the default route to the default gateway) so you should only care about setting its default gateway and nothing else...