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InterVLAN routing and Default Gateway issues

Hi Fellow Techies,

I've been trying to tackle this problem for 2 weeks or so and it has become irritating finally I thought i should get your thoughts on this problem. What am i missing ?

This is part of my homelab infrastructure.

InterVLAN routing is working flawlessly, meaning i can ping all vlans and its hosts.The problem is that i can't reach the router 192.168.1.254 from any of my VLANs, though i can reach 192.168.1.1 which is the routed interface (Fe 0/15) on Layer 3 switch.Furthermore i can reach 192.168.1.254 from the layer 3 switch but not from the VLANs

Here is the config from 3550 L3 switch

1

isis#sho run

2Building configuration...
3
4Current configuration : 5711 bytes
5!
6version 12.1
7no service pad
8
9!
10hostname isis
11!
12!
13ip subnet-zero
14ip routing
15!
16no ip domain-lookup
17!
18spanning-tree mode pvst
19spanning-tree extend system-id
20!
21!
22interface FastEthernet0/15
23description To Internet
24no switchport
25ip address 192.168.1.100 255.255.255.0
26
27!Interfaces 0/17 to 0/32 belongs to VLAN 20
28!link to saber
29interface FastEthernet0/17
30switchport access vlan 20
31switchport mode access
32no ip address
33
34
35!link to pegasus
36interface FastEthernet0/18
37switchport access vlan 20
38switchport mode access
39no ip address
40
41
42
43!link to icarus
44interface FastEthernet0/19
45switchport access vlan 20
46switchport mode access
47no ip address
48
49
50!Interfaces 0/34 to 0/48 belongs to VLAN 10
51!link to deadalus
52interface FastEthernet0/34
53switchport access vlan 10
54switchport mode access
55no ip address
56!
57
58interface Vlan1
59no ip address
60!
61interface Vlan10
62ip address 10.10.10.1 255.255.255.0
63!
64interface Vlan20
65ip address 10.20.20.1 255.255.255.0
66!
67ip default-gateway 192.168.1.100
68ip classless
69ip route 0.0.0.0 0.0.0.0 192.168.1.254
70ip http server
71!
72!
73alias exec c conf t
74alias exec s sho ip int br
75!
76end



Pings From Layer3

isis#ping 192.168.1.254

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.254, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

isis#ping 192.168.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms

isis#ping 10.10.10.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.10.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms

isis#ping 10.10.10.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.10.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

isis#ping 10.20.20.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.20.20.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

isis#ping 10.20.20.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.20.20.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

isis#ping 10.20.20.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.20.20.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/4 ms

I can reach my file server pegasus from my workstation saber, and i can reach deadalus which is my ESXi server from saber as well, meaning InterVLAN routing is working.

I've tried equivalent config on Netgear GSM7312 L3gigabit switch and 3COM/HP 4924 L3 gigabit switch and the issue remains unsolved.

Thanks for your support.

teknet.jpg

Everyone's tags (3)
1 REPLY

InterVLAN routing and Default Gateway issues

What router do you have? It sounds like the problem is that your router doesn't know about any of your other subnets. If you have the option, you will need to add static routes on the router pointing to your switch (192.168.1.100). The problem that you'll then have is that your router will need to be able to nat all of those other subnets in order to be able to give internet access. The router probably only has 192.168.1.0/24 as an internal subnet and doesn't know about the 10.10 and 10.20. subnets.

HTH,
John

*** Please rate all useful posts ***

HTH, John *** Please rate all useful posts ***
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