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i have two computers.

computer A network devices:

dev   address
-------------
wlan0 192.168.1.2
eth0  10.42.0.1

computer A routing table:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    0      0        0 wlan0
10.42.0.0       10.42.0.1       255.255.255.0   UG    0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
192.168.1.0     0.0.0.0         255.255.255.0   U     0      0        0 wlan0

computer B network devices:

dev   address
-------------
eth0  10.42.0.2

computer B routing table:

Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.42.0.1       0.0.0.0         UG    0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0

So computers A and B are connected via ethernet through a switch and computer A is connected to another network (192.168.1.0) though a wireless router (192.168.1.1). I thought this setup would connect the two networks.

On computer B, I try to ping the wireless router

ping 192.168.1.1

I'm running iptraf on computer A and I can see the request being routed through computer A

ICMP echo req (84 bytes) from 10.42.0.2 to 192.168.1.1 on eth0

but there is no response.

I thought I understood the route table but I guess I was wrong. Please help!

EDIT:

I added an entry in the wireless router routing table:

Destination LAN IP Subnet Mask    Gateway      Interface
0.0.0.0            255.255.255.0  x.x.x.x       WAN (Internet)
0.0.0.0            0.0.0.0        x.x.x.1       WAN (Internet)
10.42.0.0          255.255.255.0  192.168.1.2   LAN & Wireless
x.x.x.0            255.255.252.0  x.x.x.x       WAN (Internet)
192.168.1.0        255.255.255.0  192.168.1.1   LAN & Wireless

and that appears to have done the trick! it works now, thanks garethTheRed

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7
  • what does sysctl net.ipv4.ip_forward show?
    – garethTheRed
    Sep 16 '15 at 20:08
  • net.ipv4.ip_forward = 0. should it be 1?
    – chuck1
    Sep 16 '15 at 20:20
  • Oh yes :-) Run sysctl -w net.ipv4.ip_forward=1 as root and try again.
    – garethTheRed
    Sep 16 '15 at 20:21
  • ok did that, but I still cant ping the wireless router (192.168.1.1) from computer B. however, there are two other devices on the wireless network and I can ping one but not the other. (both can be pinged from computer A). very confused
    – chuck1
    Sep 16 '15 at 20:32
  • Do these devices have a firewall? Also, you'll need to have a static route on the router that sends traffic for computer B to computer A, otherwise it will send it down your wireless device's default route.
    – garethTheRed
    Sep 16 '15 at 20:35
2

I added an entry in the wireless router routing table:

Destination LAN IP Subnet Mask    Gateway      Interface
0.0.0.0            255.255.255.0  x.x.x.x       WAN (Internet)
0.0.0.0            0.0.0.0        x.x.x.1       WAN (Internet)
10.42.0.0          255.255.255.0  192.168.1.2   LAN & Wireless
x.x.x.0            255.255.252.0  x.x.x.x       WAN (Internet)
192.168.1.0        255.255.255.0  192.168.1.1   LAN & Wireless

and that appears to have done the trick! it works now, thanks garethTheRed

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