[SOLVED] no route to 127.0.0.0

[happybunny]

So why would my machine not have a route back to itself?

route:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
155.49.9.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
155.49.222.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
192.168.80.0 * 255.255.255.0 U 0 0 0 eth0
155.49.111.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
155.49.113.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default 192.168.80.254 0.0.0.0 UG 0 0 0 eth0


This machine cannot ping itself, but it can ping outside...plus others can ping it.

I have tried the

route add -net 127.0.0.0 dev lo

but it doesnt' come out right....

thoughts?

[Dancen]

I think the local loopback address is 127.0.0.1, try using that instead.

[happybunny]

right, it is, but look at this working route table:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
10.10.10.0 * 255.255.255.0 U 0 0 0 eth0
172.16.10.0 * 255.255.255.0 U 0 0 0 vmnet1
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
127.0.0.0 * 255.0.0.0 U 0 0 0 lo
default 10.10.10.100 0.0.0.0 UG 0 0 0 eth0


Thats what I am hoping to mirror....

any ideas why its missing from the first table or how I can add it back?

[serz]

Is the loopback interface up? If not, then do ifconfig lo up.

[leonpmu]

Simply do an ifconfig and see if the loopback device is up, also you can simply ping 127.0.0.1 to see if it is up.

[happybunny]

yes and yes....

ifconfig:

eth0 Link encap:Ethernet HWaddr 00:50:56:5C:55:1D
inet addr:192.168.80.17 Bcast:192.168.80.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:68301 errors:0 dropped:0 overruns:0 frame:0
TX packets:7585 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:10149802 (9.6 Mb) TX bytes:741955 (724.5 Kb)
Interrupt:9 Base address:0x1080

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:57 errors:0 dropped:0 overruns:0 frame:0
TX packets:57 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:8231 (8.0 Kb) TX bytes:8231 (8.0 Kb)

[root@lnvdev009 root]# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
155.49.9.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
155.49.222.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
192.168.80.0 * 255.255.255.0 U 0 0 0 eth0
155.49.111.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
155.49.113.0 192.168.80.1 255.255.255.0 UG 0 0 0 eth0
169.254.0.0 * 255.255.0.0 U 0 0 0 eth0
default 192.168.80.254 0.0.0.0 UG 0 0 0 eth0


No route to 127.0.0.0

[serz]

Again, the loopback is 127.0.0.1, not 127.0.0.0.

[retsaw]

Actually the loopback is from 127.0.0.1 to 127.255.255.254, 127.0.0.1 is the most commenly used one. 127.0.0.0 is (I believe) the network id and 127.255.255.255 is the broadcast address. So when you have 16777214 loopback IP addresses to choose from, why are you trying to ping the network id?

[soulestream]

wouldn't that be a network broadcast loopback?

i uh don't know if you can do that.



soule:confused:

[jumpedintothefire]

Think your missing the subnet from your route command,

route add -net 127.0.0.0/8 dev lo

That is a workaround, what the real problem is the route is not set when the interface comes up, that need abit of investagation. Without using the above command, what does "ifdown lo" "ifup lo" do to the routing table?

[happybunny]

YAAA!!

I have a 127.0.0.0 route now! Thanks!

it was the
route add -net 127.0.0.0/8 dev lo

that did it.

Also of note: Im a moron. The whole "i cant ping" issues were my own doing...i had the wrong subnet in my /etc/hosts file like a moron.

I have rebooted, ifup/downed lo dozens of times and still no 127.0.0.0 route.

I will simply add this to /etc/rc.d/rc.local to get it "installed" everytime i guess.

thanks
happy