Cisco 52 port SG-300 port routing

[MDSCiscoTech]

Have a scenario where 2 Cisco 3560 POE switches are linked together at different physical locations via fiber link.

On each 3560 there is a default route that 0.0.0.0 0.0.0.0 FastEthernet0/1

On each 3560 a static ip is assigned to the above port which is in trunk mode, and has fiber connected at each opposing router in those ports

I am replacing one 3560 with a Cisco SG-300 52p

****On the Cisco SG-300 52p when I assign the proper IP to the proper port and set it to trunk mode all is well but when I try to create a route similar to the 3560's I don't have that option, through gui and/or CLI I'm only able to add a static route to the "next hop".

??How can I assign a route that goes directly out the interface as is stated in the scenario described at the beginning of this question and allow traffic to traverse the fiber port between the Cisco SG-300 and Cisco 3560 over the fiber connection? 

[devils_advocate · Accepted solution]

I don't have an SG300 in front of me so can't check but try and get onto the CLI via SSH/Console and see if the option is there:

ip route 0.0.0.0 0.0.0.0 ?

If not then perhaps its not a supported feature.

The SG300's are Small Business and the Catalyst are Enterprise so you can't expect the same features.

It sounds like you have a point to point link between the switches with an IP address on the Fa0/1 port at each end. Why can't you point at the corresponding IP on the other switch?

To clarify, you have a Routed port on both switches, not a Trunk.

A Trunk is a Layer 2 port which carries traffic for multiple L2 Vlans, once you give your Ports an IP address they become Layer 3 Routed Ports. 

[MDSCiscoTech]

I have an ip address assigned to the port on the SG300 is listed as 4096 rather than being a member of any vlan, SG300 is in layer 3 mode. The challenge appears to be that traffic flows between the existing 3560's the way they are set up, swith A has ip assigned 172.X.X.1/30 with a route allowing 0.0.0.0 0.0.0.0 FastEthernet0/1 and switch B has ip assigned 172.X.X.2/30 with a route allowing 0.0.0.0 0.0.0.0 FastEthernet0/1 ------ these 2 existing switches connect correctly, they allow traffic out the interface which are both in like network range so they both just communicate effectively, when I assign the ip address 172.X.X.2/30 to the SG300 I don't seem to be able to assign a route  0.0.0.0 0.0.0.0 GigabitEthernet1.....I can assign a default rout 0.0.0.0/0.0.0.0.0/172.X.X.1/30(the ip address on the opposing router)but it doesn't reply as expected.

[devils_advocate · Accepted solution]

"port on the SG300 is listed as 4096"

Yes, the SG300 probably lists it as a 'Trunk' with 4096 as its Vlan, this is normal from the GUI perspective on these switches.

Can you provide the config on both switches?

To clarify, the SG300 Port 1 is connected to the 3560 Port 1 and they have a /30 point to point subnet between them?

Thanks

[MDSCiscoTech]

In fact switch A(3560) main building has IP assigned to fastethernet 0/1 and switch B(3560) has IP assigned to FastEthernet0/7. But the port number should have no impact, the new SG300 has the IP address on gi48.

[MDSCiscoTech]

In the scenario I'm attempting to replace switch B with the new SG300

[devils_advocate]

Interesting, well the config looks fine.

From the 3560 side (with the SG300 plugged in), can you run the following commands:

#show ip route 172.16.1.2

#show mac-address-table interface fa0/1

#show ip arp 172.16.1.2

#show interface fa0/1

Post back the results.

Thanks

[MDSCiscoTech]

I only wish I could the business is basically 24/7 and my next available testing window will be early tomorrow morning like 4 a.m. I had to swap the fiber back into the 3560 (switch B) to resume normal operations after the SG300 didn't perform as expected on this last Sunday. The interesting thing was that when I telneted into the SG300 I could ping the 3560 at the other end of the fiber and could ping locally attached items on that switch i.e. access points by IP address etc successfully-(only while in telnet)., I could ping the interface 172.16.1.1----(only while in telnet to the SG300) but....During the telnet session to the SG300 I could initiate a telnet session to the 3560 and try to ping back to the SG300 but the only response I get is from the 172.16.1.2 on the interface to which the fiber is attached. the SG300 ip or devices attached to vlan do not reply........If I'm just attached to a vlan port on the SG300 in normal mode I get no response from anything except the SG300 or other devices connected to vlans on the SG300 locally.

[devils_advocate]

Ahhh ok, we need to see what the switches think is going on to help further really.

I noticed that Switch A has a static route for the 10.2.x.x network out Fa0/1

ip route 10.2.0.0 255.255.0.0 FastEthernet0/1

Presumably you have not changed the port on Switch A when using the SG300, its still Fa0/1?

How about changing the above static route to use the next hop IP instead of the outgoing interface, i.e.:

ip route 10.2.0.0 255.255.0.0 172.16.1.2

[MDSCiscoTech]

I had considered doing that but due to time constraints didn't have a chance, Yes the port FastEthernet0/1 on Switch A is still running that same config and the fiber is still connected there, is it possible to add ip route 10.2.0.0 255.255.0.0 172.16.1.2 to Switch A without removing the existing interface route? My concern is since this is a production environment I am cautious about removing currently functioning routes that keep things running.

[MDSCiscoTech]

Theoretically as long as I do a wr mem on the 3560 to make sure the running config is copied to the startup before making any changes then I could do:

........................................

config t

no ip route 10.2.0.0 255.255.0.0 FastEthernet0/1

ip route 10.2.0.0 255.255.0.0 172.16.1.2

AND DO NOT DO - "wr mem"

.......................................

and then swap fiber into the designated port on the 300 and test, depending on result whether it succeeded or failed I could just restart the 3560 and it would reboot with the production environment config