Help Needed: PC Can't Ping Gateway on L3 Switch - Packet Tracer

[lukpox01]

Hi everyone,

I'm working on a project in Packet Tracer 8.2.2 and I've hit a wall with a connectivity issue. I've been troubleshooting for a while and would really appreciate a fresh perspective, as I'm sure I must be missing something.

The Goal:
A simple multi-VLAN network where a Layer 3 switch (Core-SW) handles all inter-VLAN routing. Access switches connect back to the core via trunks.

The Problem:
My main issue is that end devices cannot ping their default gateway. For example, a Mgmt-PC in VLAN 10, connected directly to an access port on the Core-SW, cannot ping its gateway address (192.168.10.97), which is the IP of the interface Vlan10 SVI on that same switch. 

Troubleshooting Steps I've Taken:

I've tried to verify the configuration from the ground up:

1. L3 Routing: I've confirmed ip routing is enabled on the Core-SW. The output of show ip route appears correct, showing all the SVI networks as directly connected.

2. SVI Status: show ip interface brief confirms that the SVIs for all my VLANs are "up/up" and have the correct IP addresses assigned.

3. Access Port Assignment: I've checked the host ports on the switches. For example, the Mgmt-PC's port on Core-SW is configured as switchport mode access and switchport access vlan 10.

4. PC Configuration: I have double-checked the static IP configuration on the PC (IP, Subnet Mask, and Default Gateway) for any typos and it seems to match the network plan.

5. Trunk Links: The links between switches are configured as trunks with matching native VLANs. show interface trunk reports their status as "trunking."

6. Spanning Tree: I checked show spanning-tree and all my active ports are in the FWD (Forwarding) state, so STP doesn't seem to be blocking them. I've also enabled portfast on the host-facing ports.

7. Component Swap: As a last resort, I've tried deleting the PC and cable, replacing them with new ones, and re-configuring from scratch, but the result is the same.

Despite all this, the most basic connectivity test (pinging the gateway from a directly connected host) fails. I feel like I'm stuck in a loop and am probably overlooking one simple but critical detail.

Would anyone be willing to look over project and point out what I'm missing? Any advice or ideas would be incredibly helpful.

Thank you

[Joseph W. Doherty · Accepted solution]

One major problem is, you have SVIs IPs assigned all the core and two edge switches using the same IPs, the gateway IPs, which should only be on the L3 core switch.

BTW, normal practice, you would only have one SVI defined on the L2 access switches for management access.  Which, in your case, would likely be a unique IP within VLAN 10.

EDIT:

Also BTW, after correcting the VLAN 30 edge switch, I could ping between it's top PC and the management PC in VLAN 10.  (I didn't try anything else.)

[Joseph W. Doherty]

BTW, I forgot to mention, on L2 switches, when you configure a SVI for management, you also often need to configure a default gateway IP too (assuming you want to hop across a L3 boundary).  Basically, for management purposes, the L2 switch is just another IP host.