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G450 arp table empty 3

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walruses

Technical User
Apr 1, 2016
68
MX
Hi, everybody, I have a question that I think has a little bit to do with networking but I hope someone can help me.

I have four g450

Three of them with about 800 ip stations on vlan 10, 100 on vlan 11 and 100 on vlan 12. When I do a "sh ip arp" on MG's I can just see the Ip and mac adresses of the phones working on vlan 10. (because only vlan 10 has an ip addess on MG?)

The fourth MG is independent in another site but is working with the same number of vlans. When I do a "sh ip arp" on MG I can not see any Ip or mac adresses of the phones working on any vlan. (because only vlan 12 has an ip address on MG and phones are assigned to vlan 10 and 11?)

I wish my redaction is clear and anybody can help.

Best regards.
 
Somewhere you need to have those other Vlan's subnets routed to be able to reach the Vlan subnet the MG ip is on. Your network person should be able to help, since this is a network function. It's not hard to do but teaching Vlan's and subnetting and using layer 3 to route for layer 2 switching is a bit more than can be done here.

Also, arp tables are dynamic. Things age out from them, and if no network packets are communicated in or out to a device there would be no arp entry for a device.
 
Yeah, so what you're describing is what you'd expect to happen if you only have one VLAN on the G450. The ARP table is there so IP packets can be put into ethernet frames and those frames need to be addressed to the MAC address of the recipient. If the recipient's IP is not in the same subnet, then the packet is put into a frame that is addressed to the MAC matching the IP of the default gateway, or whatever IP is the next hop to reach that subnet.

Now, G450s, even IP Offices, can be routers and the G450 has a whole layer 2 switching brain built into it too. Look at the MM314 module for a G350 - it's a 24 port POE module that the gateway can control!

That all being said, generally speaking, none of the deployments I've worked on would go to the trouble of configuring a G450 with more than 1 VLAN or using any of the networking functions that are already built into the existing data network.

There are reasons you could/would do this. I've always used VLAN 1. The S8300 server in V1 also defaults on VLAN 1 on System Platform. If you wanted to have a S8300 in one of those G450s on System Platform, there's a special script to run on it to change the VLAN.

In Aura 7, there's also out-of-band management available. That's to say that you could have the S8300 have one subnet/IP range for in-band stuff like procr/Branch Session Manager and another range for management access - then you'd start getting into needing to VLAN trunk the S8300 port on the backplane and figuring that out on the G450 to get it out too.

But, generally, it's nice and easy to have everything be VLAN 1 on the G450, and then the on the next switchport it connects to, the network admin just says "this port's default VLAN is 10" so that it treats all untagged traffic from your G450 (or traffic on the default VLAN, 1) as belonging to VLAN 10 or whatever else they wanted to call it.
 
I really appreciate your help now the situation is clear and I will work with networking team to adjust configurations.

Warm regards!!
 
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