How can I display the routing table with netmasks

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Level 1

8 points

How can I display the routing table with netmasks

I would like to see the current routing table of my MBP. The command "netstat -rn" doesn't display the associated netmasks for the IPv4 entries (but does for IPv6). Example (output shortened):

root# netstat -rn

Routing tables

Internet:

Destination Gateway Flags Refs Use Netif Expire

127 127.0.0.1 UCS 0 0 lo0

192.168.1 link#9 UCS 5 0 en3

Instead of "127" and "192.168.1", I would expect "127.0.0.0/8" and "192.168.1.0/24".

Any idea?

Thanks,

Marc

MacBook Pro (Retina, Mid 2012), OS X Mountain Lion (10.8.5)

Posted on Oct 11, 2013 2:05 AM

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Answer 1

Top-ranking reply

Moergi Author

Level 1

8 points

Oct 13, 2013 11:54 AM in response to Linc Davis

This is not exactly true, as 192.168.1 (meaning 192.168.1.0) could mean any network number from /24 to /32. But playing arount with the routing table has showed: if the netmask equals the natural class, no netmask is shown. If it differs, the netmask is shown:

192.168.1 link#4 UCSI 3 0 en0

192.168.2/25 192.168.1.1 UGSc 0 0 en3

192.168.2.128/28 192.168.1.1 UGSc 0 0 en3

Thanks anyway.

Cheers,

Marc

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Answer 2

Linc Davis

Level 10

209,739 points

Oct 11, 2013 5:42 PM in response to Moergi

Instead of "127" and "192.168.1", I would expect "127.0.0.0/8" and "192.168.1.0/24".

Those expressions mean exactly the same thing.

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