Inter vlan routing: Ping one way and not the other way around

[trickylalit]

I have attached the document with set up for reference.

I can ping from PC in one  VLAn to another but not the other way around, please see the  attached document with layout.

Not sure what am I missing here.

Thank you very much.

[mattjones03 · Accepted solution]

Hi,

So you have a trunk interface between three switches/routers, with a PC sat in each vlan?

When pinging from PC A to PC B, you receive a response?

Some things to check;

1. If these are Windows workstations, determine if they have a firewall on them denying the ICMP traffic, thus preventing your ping from working.

2. If your workstations are in different VLANs, are the workstations default gateways connect.

If possible, share a "show run" output from each of the switches/routers, as this may lead to more questions, or a potential resolution.

[trickylalit]

Hello Matt, Hussey,

Thank you fore reply. Please find trimmed output. Let me know if you need something else.

I changed the mask on switch B and Switch C as suggested, still same result. Can ping one way which was before.

I may not have access to the equipment for 2-3 days so may be little late to get more output as needed.

[mattjones03]

Hi,

I would need to see the full output of "show run"

[trickylalit]

please find run

[mattjones03]

Hi,

Thanks, can you let me know which interfaces the affected PCs are attached to?

[trickylalit]

hello Matt,

It is in the spreadsheet. PC B connected to port 5 Switch B

PC C connected to Port 6 Switch C.

Thank you for assistance.

[mattjones03]

Thanks,

When reviewing the spreadsheet it appears with boxes and no information. Must be a compatibility issue with my smartphone spreadsheet client.

Thanks for the information.

[chrihussey]

Which ports are used to connect Switch A to B?

And back to Matt's original question, are you sure PC C does not have a firewall enabled?

Thanks

[trickylalit]

hello Hussey,

T1-T1  A-B

g1/0/48-Gi 1/0/48  B-C

Its in diagram for visualization.

I pinged from this laptop B connecting wireless on our network and it pings fine.

When I am testing, I am disconnecting it off wireless and leave with Ethernet with static IP as shown in diagram

Thank you for assistance

[chrihussey]

Doesn't look like you have vlans configured on the C switch.

[trickylalit]

Hello Hussey, why do you say that

When I run Sh vlan, I see

 Vlan1    all other ports

Vlan 2    active gi 1/0/5

Vlan 3      active gi 1/0/6

Vlan 4  active

Only thing I see different in Switch B is:

vlan internal allocation policy ascending
!
vlan 2-4

I don't know why I have this line, which I don't have in switch A or C

[chrihussey · Accepted solution]

So I'm guessing you are doing VTP in server or client mode on Switch A and C, that is why you don't see the VLAN configuration those switches. When you do transparent on B, it ends up in the config.

That aside, after looking at your Excel again, the only thing that doesn't work is that PC C won't respond to pings. I think there may be layer two connectivity, but the problem is with PC C. How about switching the connections and IPs of the PCs to each other's switch ports and see if the issue follows the PCs or stays with the network?

[trickylalit]

Thank you Hussey,

I swapped PC C with another laptop and it got going.

Matt , thank you . I should have looked at testing another machine right away. I will have to check why that laptop didn't work.

Now, I do have related question on this PC C, while testing, as long as default gateway is 10.6.0.250 or 10.6.2.23 or 10.6.0.1 or 10.6.2.1 or 10.6.3.1. It is able to identify network and I can ping PC B. I have Vlan1 as 10.6.0.1 , Vlan 2 as 10.6.2.1 , Vlan 3 as 10.6.3.1.

But when I set default gateway as 10.6.1.1 or 10.6.4.1 and above. It is not able to identify network under network connections on laptop and you cannot ping PC B.

My confusion arise from why when I set 10.6.0.250/10.6.2.23 for this PC C (10.6.3.11 255.255.255.0), it is still able to ping PC B(10.6.2.10 255.255.255.0 10.6.2.1) since those two value 10.6.0.250 and 10.6.2.23 don't exist.

Thanks again everyone for all the help.

[chrihussey]

Looks like you have an incorrect mask on the VLAN 1 interfaces on switches B & C. That's probably what is causing your issue.