Can ping management IP of SG300 L2 from everywhere, except PC.

[andreas.moussaud1]

Hello,

I can ping multiple switches from my PC in the management Subnet/VLAN except one I added recently. (SG300 L2)

This last one is reachable from all of my switches and I can see his MAC address plus IP address from the core network.

But from my PC, the ping fails.

The trunk between switches is right configured, because when I type the "show ip arp" command I get the right IP, Mac address and VLAN. All of the phones, PCs plugged into this switch also have access to the internet and CUCM.

On the other hand I can perfectly reach any of the other switches from my PC, so it prooves that I can reach my management VLAN. (gateway routing from the data VLAN to the management VLAN)

[chrihussey · Accepted solution]

Sounds like your PC is OK, but is it on a different subnet than the new switch? If so is there a default gateway specified on the new switch? Can the switch ping anything off it's local management VLAN?

[andreas.moussaud1]

Yes my pc is in 172.16.X.X/16 subnet and the switch in the 172.17.X.X/16 subnet

However the core network (managed from another society) is effictively routing from DATA VLAN to Management VLAN because I can ping all the switches in this VLAN from my DATA VLAN

I have no remote access to the SG300 switch at the moment but I have not configured a default gateway.

I don't remember which Ip's the switch can ping

However, another L2 CISCO switch with a similar configuration has simply one IP address of management and no default gateway and can be access from everywhere.

So why should I add a default gateway on my L2 switch ?

When doing sh ip arp on the gateway :

Internet  172.17.X.X           56   XXXX.XXXX.XXXX  ARPA   Vlan3

(I replaced actual IP and mac address by X)

Everything seems to be fine from the switches perspective !

[chrihussey · Accepted solution]

Without a default gateway the switch will not know how to get off its local subnet. A default gateway is in our standard configs when deploying any switch. Don't know how your other switch is accessible without it.

If it isn't a default gateway issue then one must look in another direction, but for now it should be one of the first things checked.

[andreas.moussaud1]

OK , I will try it as soon as possible and keep you posted. Thanks for your answer 

EDIT  : Adding a default gateway solved the problem