cisco router

BilalButt62333 · ‎10-07-2022

I have the following scenario:

1. old Router(fast 0/0)---switch---PC

in this scenario, pc IP has 10.10.0.86 and can ping router IP 10.10.10.25

2. New Router(gig 0/0)---switch---PC

in this scenario, pc can't ping while the same IP and same config on the new router

pc can ping the old router IP(10.10.10.25) but when a new router attach with the same config pc can't ping, if pc attached directly while the pc IP (10.10.10.25) with the new router gig 0/0 it can ping

on router eth fast 0/0 has config:

IP address 10.10.10.25 255.255.255.248

IP nat inside
IP virtual-reassembly in
duplex auto
speed auto

pc has IP 10.10.0.86

NetworkDave · ‎10-07-2022

BilalButt62333,

Verify the IP settings in the PC and Routers.

old Router(fast 0/0)---switch---PC
IP 10.10.10.25 ? 10.10.0.86?
255.255.255.248? Subnet mask ?
Gateway ?

New Router(gig 0/0)---switch---PC
IP Address? IP Address?
Subnet mask ? Subnet mask ?
Gateway ? Gateway ?

Is the PC's IP address 10.10.0.86 or 10.10.10.86 or 10.10.10.25?

You mentioned that router eth fast 0/0 has config:
IP address 10.10.10.25 255.255.255.248 (is this correct?)
A Subnet Mask of 255.255.255.248 will only allow for a block of 8 IP addresses (1 Subnet ID, 6 Hosts, and 1 Broadcast). This puts the PC and router in different subnets.

You connected the PC (10.10.10.25) directly to the new routers interface (gig0/0); wasn't that the IP of the router's interface? Then what is the IP address of gig0/0?

What model are the old and new router? What model of switch? Any VLANs? if so, ROS or L3 Switch?

Please provide the running-config for both routers (old and new).

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