Very simple setup . . . PC - Switch connections, layer 2-3 switches

skywola

This is a real simple setup. Windows PC

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3550 Cisco Catalyst Switch

First question is, if I want to determine if my switch is a layer 2 or layer 3 device, can I do this:

SW2(config)#ip default?
default-gateway default-network

If I get this "default-gateway" as an option, versus default-route, can I therefore assume it is a layer 2 switch, or is that just assuming to much? So the real question is, how do you tell a layer 2 switch from a layer 3 switch?

Second question.
PC IP Address is 72.201.54.51 Switch VLAN IP is 72.201.54.55
Should I be able to ping 72.201.54.55 from my PC? The reason I am asking is, I tried it, and it did not work.

networker050184

No that is not a way to tell. You can tell by the model and use show commands to determine if ip routing is enabled.

Whether you can ping or not depends on a lot of factors.

mackenzae

If it is a cisco device - the model number usually is a good telling sign, like 3550(as your device is),3750, or 3850 are layer 3 devices based on the first digit, 2960, 2950, etc.. are layer 2. Will it let you enable ip routing? its layer 3 capable. If not its layer 2.

Your second question - Are the subnet masks configured the same on the switch and on the PC?

skywola

Yes, I did an ipconfig on the PC first to make sure that I matched the subnet mask on the switch to that of the one used on the PC.
The switch is set up with just plain old VLAN 1, with all the ports under VLAN 1. Thanks for the info on the switch model number, it was so obvious I overlooked it!

The arp table on the switch looks like this:
Protocol Address Age (min) Hardware Addr Type Interface
Internet 72.201.24.1 0 0012.d954.5ca3 ARPA Vlan1 < - - - The default gateway to the internet
Internet 72.201.24.51 42 0860.6ed4.5453 ARPA Vlan1 <- - - -This is the PC
Internet 72.201.24.55 - 0008.a3af.1c00 ARPA Vlan1 < - - - The VLAN IP is here

So here is what I do:
ping 72.201.24.55 (ping the switch from the PC)
Pinging 72.201.24.55 with 32 bytes of data:
Reply from 72.201.24.55: bytes=32 time=32ms TTL=255
Request timed out.
Request timed out.
Request timed out.


Now I do a repeat:
ping 72.201.24.55 (ping the switch from the PC)
Pinging 72.201.24.55 with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

So the first ping request (the first ethernet frame sent out) works, but the other three fail, and then when I repeated the ping request, all failed. So I am just not sure how this could be explained from a technical standpoint.

Pinging the PC from the switch, I get:
SW2#ping 72.201.24.51
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 72.201.24.51, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

I'm beginning to think this is a Windoze issue, firewall or something of that nature . . . . I hooked up my laptop to the switch, and it was able to ping the switch, no problem, but it could not ping my Desktop PC

DCD

What is the image on the switch and did you turn on routing?

Simrid

The PC's may or may not be able to ping, you need to check the subnet masks to make sure they're in the same network and check they're in the same VLANS too.

james43026

The only way to actually tell if a switch is layer 3 capable, is by looking at what IOS is running on it with a sh version, and by checking to see if you can enable ip routing from global config. As a Cisco 3750 can have a layer 2 image on it in the form of an SMI image, instead of a layer 3 image in the form of an EMI image.