Slow SSH

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Dec 2nd, 2007
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I'm running a 1721 with a vpn running config.

SSH between local area computers is fine, but very slow at logging in externally to server on the LAN.

SSH to the 1721 is fine, but anything through this is slow to log on. Speed seesm to pick up once the ssh client has finaly made the connection.

Is this something to do with the router, or more of the fact that the ssh deamon is slowing it down. I've read about putting a reverse dns entry into the hosts file (im running freebsd) but try that and nothing....

Is anyone able to help further

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Joe Clarke Sun, 12/02/2007 - 09:58
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Running ssh with -vv on the client side might give you more of a clue as to where the slowdown lies. You can also run sshd with "-D -ddd" on the server side to get a lot of debugging output there.

Typically, a reverse lookup problem would manifest itself in a delay getting the initial server prompt. Make sure you added the correct client IP to the server's host file. And depending on the version of FreeBSD, check /etc/host.conf or /etc/nsswitch.conf to make sure you're configured to look at the hosts file before dns.

rjdavison Tue, 12/04/2007 - 06:05
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Thanks. I've got a WIC-1ADSL in the 1721 with a public IP address of 83.**.**.101. The FastEthernet interface of the 1721 that is connected to the switch has an IP address of The 1721 is called

There is a delay in getting the intial server prompt so guess it is getting hung up somewhere doing a reverse lookup.

In the /etc/host file, what ip address do I use. I've seen some articles saying that its the public address (83.**.**.101), some say the internal address (

Joe Clarke Tue, 12/04/2007 - 07:35
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You need to add the client's IP (the one initiating the SSH connection) as seen by the FreeBSD server.


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