InterVLAN routing issue

Question

I've got one L3 Quanta switch. Having a bit of trouble in understanding the right way to configure VLANs and inter-VLAN routing on it. Routing on the switch is enabled.

Ports 0/3 - 0/40 are configured in VLAN 40 and are successfully receiving IP addresses from the IP helper (DNS server). This is the configuration for them:

interface 0/x
switchport allowed vlan add 40
switchport native vlan 40
exit

On port 5 I need to set up VLAN 41 which will be used for management on a few other servers. So I've done the following:

interface 0/5
switchport access vlan 41
switchport allowed vlan add 41
routing
exit

Also, I've set VLAN interface 41:

interface vlan 41
ip address 192.168.41.253 255.255.255.0
exit

On interface 0/5 I've connected device with static network configuration (to test if it's working) as follows:

ip: 192.168.41.100/24
gateway: 192.168.41.253

Pinging 192.168.41.253 from the switch obviously works. Pinging 192.168.41.100 doesn't. Same goes when I try to ping from hosts in VLAN 40.

Apparently I've misconfigured it. I'll be grateful if someone could point me in the right direction. Let me know if additional info is required.

Answer 1

I'm not familiar with Quanta, but generally, on a L3 switch...

... with regards to interface0/5 from your example:

• either a port is a Layer 3 port [1] (hint: the "routing" keyword), and it needs an ip address and is (internally) attached to some routing instance of the given L3 switch. [2]
• or a port is a layer 2 port, and as such part of one (or more, if 802.1q) VLAN(s) (hint: "switchport access vlan XX"). Then a second L3 interface is needed (for example an interface vlan XX) , and must be attached to the same routing instance as the other interface vlan yy (or the other Layer 3 port) [2]

in other words:

• either configure interface0/5 as pure routed port and give it the ip address you had on interface vlan 41, and remove the switchport commands from it. Then add interface vlan 40 with suitable IP addressing, and the L3 engine will forward (read: "route") between VLAN40 and interface0/5.
• or remove the routing keyword (a bit guessing here) from interface0/5, and leave the rest, which configures it as switchport in vlan 41. The L3 resp. IP part of VLAN 41 is handled by interface vlan 41 just as you already configured it. Then add interface vlan 40 with suitable IP addressing, and the L3 engine will forward between interface vlan 40 and interface vlan 41 [3].

---

[1] intentionally omitting the case of 802.1q tagged subinterfaces of a layer 3 port.

[2] without further special config, this will be the "default routing table", or "global table", or "default routing instance" or "default VRF" - Names do vary across vendors.

[3] end systems/hosts in VLAN41 and VLAN40 should use their respective addresses of interface vlan40/41 (or interface0/5) as gateways to get to "the other subnet"; in the most simple case in the form of default gateway, or as "next hop" or "gateway address " in additional static routes.

Answer 2

A bit late to answer, but anyway... my issue is resolved in the most bizarre way. I tried all mentioned suggestions, and still couldn't the routing to work. Finally I left the below config, and on my core switch (the one that the Quanta is uplinked to) I deleted the route, re-added it and things started to flow (?!). Now VLANs 40 & 41 are reaching each other, no matter if I use the Quanta interfaces as gateway, or my core switch.

Anyway, here's my working config right now on port 0/5:

interface 0/5
switchport access vlan 41
switchport allowed vlan add 40-41
switchport native vlan 41
exit