07-22-2012 05:44 AM - edited 03-07-2019 07:54 AM
Hi,
I was building a small network in Cisco Packet Tracer and ran in to an issue. I have 4 routers running OSPF, and off one of the routers I have 5 3560 Multilayer switches. The router that the switches hang off of, I have a sub-interface with dot1q encapsulation, set for vlan 10 and an IP Address. 10.14.16.1/24. The switches have interface vlan 10 configures, and have IPs in the same subnet. From that router, I can ping/telnet to all the switches without issue. My problem arises when I try and reach those switches from any other router. OSPF is set to redistribute static and connected subnets.The routing table is populated correctly on all the routers. When I ping and trace the packet, it looks like it makes it all the way to the respective switch, but the packet never makes it back. I've played with the default route on the switches to no avail. Am I trying to implement this incorrectly, or am I just missing something?
Solved! Go to Solution.
07-22-2012 07:42 AM
Hi Chris,
the problem is that you are missing the default gateway.
When you are configuring L2 switch (or L3 switch with no ip routing command) you need to set up default gateway (such as when configuring PC's) so that switch will know where to send packets that are destined for other networks, outside LAN.
So the problem lays in your switches configuration.
The problem in packet tracer is that you can't issue ip default-gateway command on Multilayer switches.
The only solution is to use either L2 switches instead of Multilayer switches or to enable ip routing with command ip routing and then you have two possibilities:
static default route, ip route 0.0.0.0 0.0.0.0 10.14.16.1
or to use ip default-network command, but I am not aware how this command works, you can study more here if you want to :
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094374.shtml#ipnetwork
Best regards,
Jan
07-22-2012 06:07 AM
Hi Chris,
can you please attach the packet tracer file so we can take a closer look at it?
Best regards,
Jan
07-22-2012 06:56 AM
07-22-2012 07:42 AM
Hi Chris,
the problem is that you are missing the default gateway.
When you are configuring L2 switch (or L3 switch with no ip routing command) you need to set up default gateway (such as when configuring PC's) so that switch will know where to send packets that are destined for other networks, outside LAN.
So the problem lays in your switches configuration.
The problem in packet tracer is that you can't issue ip default-gateway command on Multilayer switches.
The only solution is to use either L2 switches instead of Multilayer switches or to enable ip routing with command ip routing and then you have two possibilities:
static default route, ip route 0.0.0.0 0.0.0.0 10.14.16.1
or to use ip default-network command, but I am not aware how this command works, you can study more here if you want to :
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094374.shtml#ipnetwork
Best regards,
Jan
07-22-2012 07:50 AM
Thanks Jan. I originally had the default route of "0.0.0.0 0.0.0.0 10.14.16.1" however I was missing the ip routing statement. Once added, everything works perfectly. Thanks again.
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