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05-03-2022 02:15 AM - edited 05-03-2022 02:16 AM
I've just configured a new internal subnet which I can ping from the router but I can't ping devices on the subnet from my computer. I have other subnets configured and they work fine. For example:
WORKS - can ping from both router and PC:
interface GigabitEthernet0/1.4 encapsulation dot1Q 4 ip address 192.168.0.251 255.255.255.0 ip nat inside ip virtual-reassembly in zone-member security in-zone
DOESN'T WORK - can ping from router but not PC:
interface GigabitEthernet0/1.140 encapsulation dot1Q 140 ip address 10.0.4.2 255.255.255.0 ip nat inside ip virtual-reassembly in zone-member security in-zone
am I missing something?
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05-03-2022 02:47 AM
Is it packet tracer? zip the file and attach here. Is easier to help. If not packet tracer, share the show run from switch and rourter.
Make sure default gateway is configured on PC.
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05-03-2022 02:26 AM - edited 05-03-2022 02:26 AM
Make sure the Router conencted to switch has VLAN allowed ( example VLAN 140)
make sure your device access connected port belong to VLAN 140
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05-03-2022 02:47 AM
Is it packet tracer? zip the file and attach here. Is easier to help. If not packet tracer, share the show run from switch and rourter.
Make sure default gateway is configured on PC.

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05-03-2022 03:51 AM
Hello,
what is the context of your question ? Post a diagram of your topology as well as the full configurations of all devices involved. You have a ZBF configured as well ?
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05-03-2022 03:57 AM
Pc dont have any ip
Pc gw is missing
Pc subnet is not included in overload nat
Check above three points
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05-04-2022 03:05 AM - edited 05-05-2022 03:12 AM
Basic topology (router is Cisco 2901):
- Local subnet: 192.168.2.* on router on 192.168.2.1 (config: spc-t1b1-core-gw3-confg11-p.txt)
- New subnet 10.0.4.* on router 10.0.4.2 (pings)
- Core switch (cisco 3750 stack) 192.168.2.2, 10.0.4.3 (pings) (config: spc-t1l1-core-sw1-confg1-p.txt)
- T1B1 switch (cisco 300) 192.168.2.14 (config: spc-t1b1-idf-sw1-p.txt)
- T1B1 switch – link to netgear switch on 10.0.4.* subnet
VLan 140 switch configuration:
Core switch 192.168.2.2 (cisco 3750 stack) – router connection:
interface GigabitEthernet1/0/11 description Router 1 switchport trunk encapsulation dot1q switchport trunk allowed vlan 4,5,10,100,140 switchport mode trunk
Core switch to T1B1 switch connection:
interface GigabitEthernet3/0/3 description Tower 1 basement 1 new switch 192.168.2.14 switchport trunk encapsulation dot1q switchport trunk native vlan 20 switchport trunk allowed vlan 20,30,60,140 switchport mode trunk
T1B1 switch – core switch connection:
interface gigabitethernet27 description "Core Connection" switchport trunk allowed vlan add 5,10,30,60,140 switchport trunk native vlan 20
T1B1 switch – link to netgear switch on 10.0.4.* subnet:
interface gigabitethernet11 description Residental switchport mode access switchport access vlan 140
To answer comments:
Context: New subnet 10.0.4.* added to network that contains a number of cameras
Network diagram: attached
Full configurations of switches and router attached (static routes and security information omitted)
ZBF: is configured but all subnets are declared “in-zone” so I assume it has no affect?
PC ip address: 192.168.2.176
PC GW: 192.168.2.1
Overload NAT applies to internet access? So not applicable as we are only talking inside NAT?
VLAN 140: configured on each device and port per configuration above
Packet tracing attached: from 10.0.4.99 pinging to 192.168.2.176 (failed) and 10.0.4.1 (success)
Conclusion: can ping from PC to router (10.0.4.2) and switch (10.0.4.3) but final subnet 10.0.4.1. Also can’t ping PC (192.168.2.176) from the new subnet (10.0.4.99 laptop). The Overload NAT question got me thinking that maybe my assumption that “ip nat inside” was enough to allow subnets to communicate in the router is incorrect. Perhaps the “ip route 0.0.0.0 0.0.0.0 Dialer6” has something to do with this (internet routing).
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05-05-2022 03:15 AM
The configuration as posted worked fine. The issue was that the devices on the 10.0.4.* network (which I don't control) did not have the gateway configured. I tested the subnets with a computer on each end, correctly configured with a GW, and it worked fine.
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05-05-2022 03:25 AM
Hi
The only file I see is the PDF with topology. Did you add more file?
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05-05-2022 04:07 AM
I decided to delete them because they were not needed to locate the problem and the code I published is enough to see a working solution.
