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Can Ping from Router but not from Switch

BDS-ASCEND
Level 1
Level 1

The diagram below illustrates a simple test network I'm working on. At present, I can ping to each end (including the Internet) from the intermediate router but I can't ping through the router from either side. I do have a route 0.0.0.0 0.0.0.0 10.1.180.1 statement on the intermediate router.

I do have another router/switch combo for our lab (2801/3560-x) that works as expected to the same layer-3 core switch.

1 Accepted Solution

Accepted Solutions

joaquin2791
Level 1
Level 1

Can you verify if the HP L3 Switch, know about the network 10.1.204.0 , 10.5.204.0 & 10.6.204.0 ?

I think that the problem is that the return traffic can't reach this networks because this HP L3 switch don't know about them.

View solution in original post

11 Replies 11

Reza Sharifi
Hall of Fame
Hall of Fame

Looking at your diagram, I don't see ip 10.1.180.1 on the 2911 router.

Can you clarify?

Can you post config from the 2960x switch?

HTH

While I can send the switch configuration, is there a specific section that is relevant to the discussion?

Why would the 2911 router have the 10.1.180.1 address? In the text I said I have the statement:

route 0.0.0.0 0.0.0.0 10.1.180.1

joaquin2791
Level 1
Level 1

Can you verify if the HP L3 Switch, know about the network 10.1.204.0 , 10.5.204.0 & 10.6.204.0 ?

I think that the problem is that the return traffic can't reach this networks because this HP L3 switch don't know about them.

I will wager that is the issue. I had forgotten the route on the core switch for the other lab network was 10.1.250.1. I will test this and post back.

That worked to get me out to the connections on VLAN 10 on the core switch. However, I can't connect to devices on other networks/VLANs like the internet (8.8.8.8) or VLAN 50.

I must have overlooked something else here. My other lab configuration works as expected. I don't see anything obvious in the configs for the two lab networks (same IP scheme, connected at different times). Instead of uploading complete configs for this switch and router, what sections would you find interesting?

joaquin2791  Do you have any thoughts on my further routing problem?

Updated drawing.

looking at your diagram below, you don't list the subnet masks, so it's hard to know if the SVI's you created on the HP switch are actually in the same subnet as what you have listed as VLAN 10, 50 and 60 on the 2911 and 2960.

 

For it to really work, assuming all nets are /24 your vlan10, 50 and 60 need to be something like on the HP switch

VLAN10 10.1.204.5

VLAN50 10.5.204.5

VLAN60 10.6.204.5

 

By having those vlans defined on your core as 10.1.180.1,10.5.180.1 etc...the only way that will work is if you are running /16 mask, otherwise they are not in the correct subnet to route from the core to the 2911 or 2960

BDS-ASCEND
Level 1
Level 1

Also, I am confused on the use of the native vlan command as in this example:

interface GigabitEthernet1/0/52
switchport trunk native vlan 10
switchport mode trunk

All my reading about this seems to indicate that I should use it on the switch port interfacing to the router. However, any time I attempt to employ that command, traffic seems to be restricted to the stated VLAN. What is the proper use of that command in a scenario like this?

Native vlan means that the trunk will carry that vlan WITHOUT a tag.

I recommend that you try always to put a tag to every vlan or type of traffic.

An important point is that if you use native vlan in that trunk, you also need that the router doesn't tag that vlan (you will need to erase the encapsulation command from the subinterface, but this also will delete the ip address from the subinterface). That's the reason I recommend that all your vlans use a tag (so the router will differentiate them)

Example 1: The switch has 2 vlans (vlan 10 & 20)

SW:

interface fa0/0

 switchport mode trunk

 switchport trunk native vlan 10

R:

interface fa0/0.10

 ip address 10.1.204.1 255.255.255.0

% Configuring IP routing on a LAN subinterface is only allowed if that

subinterface is already configured as part of an IEEE 802.10, IEEE 802.1Q,

or ISL vLAN.

==> If I want 2 vlans in my switch I will need to use tags in both.

==> This solution will work if you only have 1 vlan, and the configuration in the router must be set in the port (not in the subinterface)