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Trouble Creating a Routing Table

Hi,

I am trying to complete an assignment for a class about subnets and routing tables. I am using the terninal shell on my Mac.

I assigned the IP address 192.168.3.1 to en0. (My teacher's instructions were to assign the address to eth0, but apparently my Mac doesn't use that interface).

Next I was told to test various network addresses and netmasks using the route command. I tried for several that should be legal, but got the error msg "illegal option -a".

Here are a couple of combinations I tried that I think should be legal:

network address: 209.220.186.96 subnet 255.255.255.224

network address: 209.220.186.240 subnet 255.255.255.240

I used the follow command to try to add them to the routing table"

route -add -net 209.220.186.96 netmask 255.255.255.224

etc.

Is there anyone that can help me and tell me what I'm doing wrong?

Thanks.

Kara

SOLUTION

kfullarton

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Gabriel Orozco

ir, if that does not work, use

route add -net 209.220.186.96 netmask 209.220.186.240 gw <destination_gateway> dev en0

problem is, you need an ip address to be your gateway to the new network. maybe it's your default gateway anyways? but you need to tell the route command that ip in order to make it work.

kara334

ASKER

Well, that sounds like it will work. But I don't know my gateway or default gateway. When I do ifconfig, I don't see it. Can you help me figure out my gateway? Thank you.

Gabriel Orozco

netstat -nr

or

route -n

should show it to you.

kara334

ASKER

Thank you again. I think I found the default gateway - 192.168.1.1. But obviously I'm doing something else wrong. (see the code below). I made a few typos along the way. But even when I think I typed everything correctly, I'm still getting an error.

Karas-Computer:~ root# netstat -nr
Routing tables

Internet:
Destination Gateway Flags Refs Use Netif Expire
default 192.168.1.1 UGSc 4 5 en0
127 127.0.0.1 UCS 0 0 lo0
127.0.0.1 127.0.0.1 UH 10 1798 lo0
169.254 link#4 UCS 0 0 en0
192.168.1 link#4 UCS 1 0 en0
192.168.1.1 link#4 UHLW 3 0 en0
192.168.1.101 127.0.0.1 UHS 0 0 lo0
192.168.3 link#4 UC 0 0 en0

Internet6:
Destination Gateway Flags Netif Expire
::1 ::1 UH lo0
fe80::%lo0/64 fe80::1%lo0 Uc lo0
fe80::1%lo0 link#1 UHL lo0
fe80::%en0/64 link#4 UC en0
fe80::20d:93ff:fe76:ce28%en0 0:d:93:76:ce:28 UHL lo0
ff01::/32 ::1 U lo0
ff02::/32 ::1 UC lo0
ff02::/32 link#4 UC en0
Karas-Computer:~ root# route add -net 209.220.186.96 netmask 255.255.255.96 gw 192.168.3 dev en0
route: bad address: netmask
Karas-Computer:~ root# route add -net 209.220.186.96 netmask 255.255.255.96 gw 192.168.1.1 dev en0
route: bad address: netmask
Karas-Computer:~ root# route add -net 209.220.186.96 netmask 255.255.255.96 gw 192.168.1.1 dev en0
route: bad address: netmask
Karas-Computer:~ root# route add -net 209.220.186.96 netmask 255.255.255.224 gw 192.168.3 dev en0
route: bad address: netmask
Karas-Computer:~ root# route add -net 209.220.186.96 netmask 255.255.255.224 gw 192.168.1.1 dev en0
route: bad address: netmask
Karas-Computer:~ root# route add -net 209.220.186.240 netmask 255.255.255.240 gw192.168.1.1 dev en0
route: bad address: netmask
Karas-Computer:~ root#
Karas-Computer:~ root#

kalifi

Hi kara334,

Why don't you try
route add -net 209.220.186.240/24 gw192.168.1.1 dev en0
just to see if that works and that change 24 to whatever you need.

Hope that will help.

Miro

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Gabriel Orozco

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kara334

ASKER

I ended up dropping this class and forgot I had a question open. Sorry for the late points.

Kara