01-29-2012 08:54 PM - edited 03-04-2019 03:03 PM
So heres my question. Im running GNS3 with multiple routers, and a cloud to bring the internet in via the host pc. I attached a screen shot of my Topology in GNS3 to give a visual of the setup. I can ping out/telnet in via the internet to the first attached router (R4 in the topology), however none of my other routers can get out. Im running EIGRP on all routers except R7, and all routes are discovered ok. R4 has a route of last resort to the gateway (10.26.7.1). I can ping all of the networks, I just cant ping out to the internet. From any router except R4, I can ping up to 10.26.7.3, but not the gateway of 10.26.7.1. Im trying to figure out what Im missing here. Can anyone shed some light?
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01-30-2012 01:02 PM
Yes, you need one or more route back on 10.26.7.1
If you add static routes, then the next hop has to be your R4, 10.26.7.3
You need to add static routes for all networks that you have in your GNS3 "cloud".
Or establish a dynamic routing protocol between R4 and your L3 switch and push the networks to L3 switch through that dynamic routing protocol.
Let me know if this works!
Calin
01-29-2012 09:44 PM
Possibly you need to run nat in order to do that or redistribute ur gateway via R4 on eigrp or use the command default-network
I will try this tomorrow and let u know
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01-29-2012 10:01 PM
I thought about NAT, and thought maybe its a GNS3 bug - however, I put an extra router on the network (R7). I can ping the IP 192.168.1.1 from R1, but cant from anywhere else. I feel like im missing some sort of static route, but I've tried a few, none seem to work.
01-29-2012 11:57 PM
Hi,
did you try pinging 10.26.7.1 when the firewall on your host is disabled ?
for internet connectivity, first nat everything on R4 to the interface linking to your host NIC and tell us if you've got still the problem in which case tell us how you connect to the internet. posting your GNS3 net file would be great also.
Regards.
Alain
01-30-2012 10:52 AM
Theres no firewall on 10.26.7.1, this is the IP of my L3 Switch. Again, regardless of that, I have the same issue with R1 and R7. R1 can ping to the 192.168.1.1 provided I have a static route set for it. However, none of the other routers can hit that IP. They can ping 16.1.1.1, but dont know how to get to R7.
01-30-2012 12:51 AM
Hello Chris,
I assume that on the box with 10.26.7.1 you have multiple interfaces. If this is a linux box,did you enable the packet forwarding between the interfaces?
cat /proc/sys/net/ipv4/ip_forward
If the result is 1 then your OK.
HTH,
Calin
01-30-2012 10:57 AM
10.26.7.1 is not a Linux box or firewall, it is my Cisco L3 switch.
01-30-2012 11:03 AM
I see there a "cloud" next to 10.26.7.1 and I thought that the is physical interface where the interface cisco router interface is bounded to.
01-30-2012 11:07 AM
It is the physical of my windows pc which is on that same subnet. Firewall on or off doesnt matter.
01-30-2012 11:15 AM
OK, so let me see if I understand:
R4 (10.26.7.3) is logically bounded to your physical NIC, which is connected to a physical L3 switch with the IP address 10.26.7.1 (how is this configured? SVI or L3 port on switch).
Am I correct?
01-30-2012 11:31 AM
Sort of. R4s interface f0/0 IP is bound to 10.26.7.3/24. My PC NIC has 10.26.7.30/24 (via DHCP) and the L3 switch IP is 10.26.7.1/24. R4 can communicate without issue to the internet/my other LANs just fine. Its the other routers who cant route out, let alone ping 10.26.7.1.
01-30-2012 11:41 AM
Just a dump question, but do you push the default-route from R4 to the rest of the routers? Can you show an output of the routing table on another router (e.g. R2)?
01-30-2012 12:20 PM
Now it sounds like what I was thinking. How would I push that default route out? Below is the routing table from R2.
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 1 subnets
D 10.26.7.0 [90/284160] via 12.1.1.2, 00:03:08, Ethernet1/1
11.0.0.0/30 is subnetted, 1 subnets
C 11.1.1.0 is directly connected, Ethernet1/0
12.0.0.0/30 is subnetted, 1 subnets
C 12.1.1.0 is directly connected, Ethernet1/1
13.0.0.0/30 is subnetted, 1 subnets
D 13.1.1.0 [90/307200] via 15.1.1.5, 00:03:08, Ethernet1/2
[90/307200] via 12.1.1.2, 00:03:08, Ethernet1/1
14.0.0.0/30 is subnetted, 1 subnets
D 14.1.1.0 [90/307200] via 15.1.1.5, 00:03:08, Ethernet1/2
[90/307200] via 11.1.1.1, 00:03:08, Ethernet1/0
15.0.0.0/30 is subnetted, 2 subnets
C 15.1.1.4 is directly connected, Ethernet1/2
D 15.1.1.0 [90/307200] via 12.1.1.2, 00:03:08, Ethernet1/1
[90/307200] via 11.1.1.1, 00:03:08, Ethernet1/0
01-30-2012 12:27 PM
On R4:
ip route 0.0.0.0 0.0.0.0 x.x.x.x (next hop to the internet, yours is 10.26.7.1 if I understood correct)) ! router eigrp xxx redistribute static default-metric 10000 1 255 1 1500
default-metric can be changed to whatever you need.
This is just a simple example to see if it's working.
Then check on R2 if you have a default route.
HTH,
Calin
01-30-2012 12:53 PM
So this looks promising....The routing table on R2 is below. I still cant ping 10.26.7.1 though. Im wondering if I need routes back in to the GNS3 network on the L3 switch now....
Gateway of last resort is 12.1.1.2 to network 0.0.0.0
10.0.0.0/24 is subnetted, 1 subnets
D 10.26.7.0 [90/284160] via 12.1.1.2, 00:34:32, Ethernet1/1
11.0.0.0/30 is subnetted, 1 subnets
C 11.1.1.0 is directly connected, Ethernet1/0
12.0.0.0/30 is subnetted, 1 subnets
C 12.1.1.0 is directly connected, Ethernet1/1
13.0.0.0/30 is subnetted, 1 subnets
D 13.1.1.0 [90/307200] via 15.1.1.5, 00:34:32, Ethernet1/2
[90/307200] via 12.1.1.2, 00:34:32, Ethernet1/1
14.0.0.0/30 is subnetted, 1 subnets
D 14.1.1.0 [90/307200] via 15.1.1.5, 00:34:32, Ethernet1/2
[90/307200] via 11.1.1.1, 00:34:32, Ethernet1/0
15.0.0.0/30 is subnetted, 2 subnets
C 15.1.1.4 is directly connected, Ethernet1/2
D 15.1.1.0 [90/307200] via 12.1.1.2, 00:34:32, Ethernet1/1
[90/307200] via 11.1.1.1, 00:34:32, Ethernet1/0
D*EX 0.0.0.0/0 [170/281856] via 12.1.1.2, 00:00:20, Ethernet1/1
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