Having trouble connecting to my home ssh server through the network at my office. The connection output is listed below. This is a laptop and I use it daily to connect from libraries, cafes, neighborly networks etc ... I suspect that the firewall at my office is interfering somehow. How would I use nc or nmap to rule that in or out?

jb@netbook:~$ ssh -p yyy user@my.server.url -i ~/.ssh/id_rsa
OpenSSH_5.1p1 Debian-5ubuntu1, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to <my.server.url> [xxx.xxx.xxx.xxx] port yyy.
debug1: Connection established.r
debug1: identity file /home/jb/.ssh/identity type -1
debug1: identity file /home/jb/.ssh/id_rsa type -1
debug1: identity file /home/jb/.ssh/id_dsa type -1
ssh_exchange_identification: Connection closed by remote host
jb@netbook:~$

Can you rerun the ssh command with -vvv

jb@netbook:~$ ssh -p yyy user@my.server.url -vvv -i .ssh/id_rsa
OpenSSH_5.1p1 Debian-5ubuntu1, OpenSSL 0.9.8g 19 Oct 2007
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to my.server.url [xxx.xxx.xxx.xxx] port yyy.
debug1: Connection established.
debug3: Not a RSA1 key file .ssh/id_rsa.
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'Proc-Type:'
debug3: key_read: missing keytype
debug2: key_type_from_name: unknown key type 'DEK-Info:'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
debug1: identity file .ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
ssh_exchange_identification: Connection closed by remote host

Have you checked the date/time on both to see how far apart they are? This has given me grief in the past and it was related to the system date skewed too much apart between the servers.

Here is what I run on all my servers to ensure they don't skew too much:

cronned as root:

Thank you for the advice. That gives me something to look in to. I'm a little skeptical though because the same laptop connects without issue everywhere else. The only location that doesn't work is behind my office firewall.