Analysis
Generally, when using
ssh -vT git@github.com, it would show as below:[dennis@localhost ~]$ ssh -vT git@github.com OpenSSH_6.1p1, OpenSSL 1.0.1e-fips 11 Feb 2013 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 50: Applying options for * debug1: Connecting to github.com [192.30.252.129] port 22. debug1: Connection established. debug1: identity file /home/dennis/.ssh/id_rsa type 1 debug1: identity file /home/dennis/.ssh/id_rsa-cert type -1 debug1: identity file /home/dennis/.ssh/id_dsa type -1 debug1: identity file /home/dennis/.ssh/id_dsa-cert type -1 debug1: identity file /home/dennis/.ssh/id_ecdsa type -1 debug1: identity file /home/dennis/.ssh/id_ecdsa-cert type -1 debug1: Remote protocol version 2.0, remote software version libssh-0.6.0 debug1: no match: libssh-0.6.0 debug1: Enabling compatibility mode for protocol 2.0 debug1: Local version string SSH-2.0-OpenSSH_6.1 debug1: SSH2_MSG_KEXINIT sent debug1: SSH2_MSG_KEXINIT received debug1: kex: server->client aes128-ctr hmac-sha1 none debug1: kex: client->server aes128-ctr hmac-sha1 none debug1: sending SSH2_MSG_KEX_ECDH_INIT debug1: expecting SSH2_MSG_KEX_ECDH_REPLY debug1: Server host key: RSA xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx debug1: Host 'github.com' is known and matches the RSA host key. debug1: Found key in /home/dennis/.ssh/known_hosts:1 debug1: ssh_rsa_verify: signature correct debug1: SSH2_MSG_NEWKEYS sent debug1: expecting SSH2_MSG_NEWKEYS debug1: SSH2_MSG_NEWKEYS received debug1: Roaming not allowed by server debug1: SSH2_MSG_SERVICE_REQUEST sent debug1: SSH2_MSG_SERVICE_ACCEPT received debug1: Authentications that can continue: publickey debug1: Next authentication method: publickey debug1: Offering RSA public key: /home/dennis/.ssh/id_rsa debug1: Server accepts key: pkalg ssh-rsa blen 279 debug1: Authentication succeeded (publickey). Authenticated to github.com ([192.30.252.129]:22). debug1: channel 0: new [client-session] debug1: Entering interactive session. debug1: Sending environment. debug1: Sending env LC_MONETARY = en_HK.utf8 debug1: Sending env LC_NUMERIC = en_HK.utf8 debug1: Sending env XMODIFIERS = @im=ibus debug1: Sending env LANG = en_GB.utf8 debug1: Sending env LC_MEASUREMENT = en_HK.utf8 debug1: Sending env LC_TIME = en_HK.utf8 Hi matrix207! You've successfully authenticated, but GitHub does not provide shell access. debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug1: channel 0: free: client-session, nchannels 1 Transferred: sent 2832, received 1816 bytes, in 1.5 seconds Bytes per second: sent 1950.6, received 1250.8 debug1: Exit status 1 [dennis@localhost ~]$But when using VPN, it show as below:
[dennis@localhost ~]$ ssh -vT git@github.com OpenSSH_6.1p1, OpenSSL 1.0.1e-fips 11 Feb 2013 debug1: Reading configuration data /etc/ssh/ssh_config debug1: /etc/ssh/ssh_config line 50: Applying options for * debug1: Connecting to github.com [192.30.252.128] port 22. debug1: connect to address 192.30.252.128 port 22: No route to host ssh: connect to host github.com port 22: No route to hostReason of the problem is that, your vpn setup routing all your traffic over
the VPN, you can update your routing table to route traffic to github back
over your ethernet interface rather than the VPNNot run VPN
[dennis@localhost ~]$ route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default 192.168.1.1 0.0.0.0 UG 0 0 0 wlan0 192.168.1.0 * 255.255.255.0 U 9 0 0 wlan0 192.168.122.0 * 255.255.255.0 U 0 0 0 virbr0 [dennis@localhost ~]$ [dennis@localhost ~]$ ifconfig lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 0 (Local Loopback) RX packets 9114 bytes 4451106 (4.2 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 9114 bytes 4451106 (4.2 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 p1p2: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 ether XX:XX:XX:XX:XX:XX txqueuelen 1000 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 virbr0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255 ether 52:54:00:f3:fa:32 txqueuelen 0 (Ethernet) RX packets 118 bytes 19982 (19.5 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 30 bytes 4505 (4.3 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 vnet0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet6 fe80::fc54:ff:fedb:760f prefixlen 64 scopeid 0x20<link> ether fe:54:00:db:76:0f txqueuelen 500 (Ethernet) RX packets 118 bytes 21646 (21.1 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 6974 bytes 365825 (357.2 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 wlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.1.100 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 fe80::c617:feff:fec3:892d prefixlen 64 scopeid 0x20<link> ether XX:XX:XX:XX:XX:XX txqueuelen 1000 (Ethernet) RX packets 39375 bytes 25884803 (24.6 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 46628 bytes 7804313 (7.4 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0Using VPN
[dennis@localhost ~]$ route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default * 0.0.0.0 U 0 0 0 ppp0 10.0.4.4 * 255.255.255.255 UH 0 0 0 ppp0 192.168.1.0 * 255.255.255.0 U 9 0 0 wlan0 192.168.122.0 * 255.255.255.0 U 0 0 0 virbr0 199.119.206.177 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0 199.119.206.177 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0 [dennis@localhost ~]$ ifconfig ... ppp0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST> mtu 1400 inet 10.0.4.123 netmask 255.255.255.255 destination 10.0.4.4 ppp txqueuelen 3 (Point-to-Point Protocol) RX packets 9 bytes 114 (114.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 11 bytes 176 (176.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 ...get ip from ping github
[dennis@localhost ~]$ ping github.com PING github.com (192.30.252.129) 56(84) bytes of data.routing tables????(NOTICE: this section is unfinished.)
[dennis@localhost ~]$ su -c 'route add 192.30.252.129 wlan0' Password: [dennis@localhost ~]$ route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default * 0.0.0.0 U 0 0 0 ppp0 10.0.4.4 * 255.255.255.255 UH 0 0 0 ppp0 ip1d-lb3-prd.ia * 255.255.255.255 UH 0 0 0 wlan0 192.168.1.0 * 255.255.255.0 U 9 0 0 wlan0 192.168.122.0 * 255.255.255.0 U 0 0 0 virbr0 199.119.206.177 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0 199.119.206.177 192.168.1.1 255.255.255.255 UGH 0 0 0 wlan0 [dennis@localhost ~]$ su -c 'route add 192.30.252.129 gw 192.168.1.1'CONTINUE