• No Proxy

• Use GNOME Proxy settings

• HTTP Proxy

• Sock 4

• Sock 5

Có. Chắc chắn luôn với...
[li]No Proxy[/li] 

Nếu dùng HTTP proxy thì phải chắc chắn rằng proxy đó cho phép tunnel 

Đùa gì?
pidgin có cho chạy ở chế độ debug, bằng cách vào menu help/"debug window" (hoặc -d). Để xác định lỗi, quanta chạy pidgin ở chế độ debug, thực hiện login rồi paste kết quả lên đây mọi người xem giúp cho.
Thân. 

[root@localhost kitty]# pidgin -d
dbus: Failed to get connection: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
plugins: probing /usr/lib/pidgin/timestamp_format.so
plugins: probing /usr/lib/pidgin/convcolors.so
plugins: probing /usr/lib/pidgin/xmppconsole.so
plugins: probing /usr/lib/pidgin/gevolution.so
plugins: probing /usr/lib/pidgin/ticker.so
plugins: probing /usr/lib/pidgin/nautilus.so
plugins: probing /usr/lib/pidgin/gestures.so
plugins: probing /usr/lib/pidgin/markerline.so
plugins: probing /usr/lib/pidgin/history.so
plugins: probing /usr/lib/pidgin/timestamp.so
plugins: probing /usr/lib/pidgin/spellchk.so
plugins: probing /usr/lib/pidgin/iconaway.so
plugins: probing /usr/lib/pidgin/notify.so
plugins: probing /usr/lib/pidgin/musicmessaging.so
plugins: probing /usr/lib/pidgin/pidginrc.so
plugins: probing /usr/lib/pidgin/extplacement.so
plugins: probing /usr/lib/purple-2/log_reader.so
plugins: probing /usr/lib/purple-2/psychic.so
plugins: probing /usr/lib/purple-2/libyahoo.so
plugins: probing /usr/lib/purple-2/ssl.so
plugins: probing /usr/lib/purple-2/libsilcpurple.so
plugins: probing /usr/lib/purple-2/libaim.so
plugins: probing /usr/lib/purple-2/libzephyr.so
plugins: probing /usr/lib/purple-2/statenotify.so
plugins: probing /usr/lib/purple-2/ssl-nss.so
plugins: probing /usr/lib/purple-2/offlinemsg.so
plugins: probing /usr/lib/purple-2/libgg.so
plugins: probing /usr/lib/purple-2/libnovell.so
plugins: probing /usr/lib/purple-2/autoaccept.so
plugins: probing /usr/lib/purple-2/libmsn.so
plugins: probing /usr/lib/purple-2/libsametime.so
plugins: /usr/lib/purple-2/libsametime.so has a prefs_info, but is a prpl. This is no longer supported.
plugins: probing /usr/lib/purple-2/libqq.so
plugins: probing /usr/lib/purple-2/dbus-example.so
plugins: probing /usr/lib/purple-2/libirc.so
plugins: probing /usr/lib/purple-2/libxmpp.so
plugins: probing /usr/lib/purple-2/libjabber.so
plugins: /usr/lib/purple-2/libjabber.so is not usable because the 'purple_init_plugin' symbol could not be found. Does the plugin call the PURPLE_INIT_PLUGIN() macro?
plugins: probing /usr/lib/purple-2/ssl-gnutls.so
plugins: probing /usr/lib/purple-2/idle.so
plugins: probing /usr/lib/purple-2/newline.so
plugins: probing /usr/lib/purple-2/libicq.so
plugins: probing /usr/lib/purple-2/joinpart.so
plugins: probing /usr/lib/purple-2/buddynote.so
plugins: probing /usr/lib/purple-2/libsimple.so
plugins: probing /usr/lib/purple-2/liboscar.so
plugins: /usr/lib/purple-2/liboscar.so is not usable because the 'purple_init_plugin' symbol could not be found. Does the plugin call the PURPLE_INIT_PLUGIN() macro?
util: Reading file accounts.xml from directory /root/.purple
util: Reading file status.xml from directory /root/.purple
stun: using server
stun: using server
sound: Initializing sound output drivers.
gtkblist: added visibility manager: 1
docklet: created
util: Reading file blist.xml from directory /root/.purple
prefs: Reading /root/.purple/prefs.xml
prefs: Finished reading /root/.purple/prefs.xml
plugins: Loading saved plugin /usr/lib/pidgin/extplacement.so
prefs: /pidgin/conversations/placement changed, scheduling save.
plugins: Loading saved plugin /usr/lib/pidgin/history.so
plugins: Loading saved plugin /usr/lib/pidgin/notify.so
pounce: Error reading pounces: Failed to open file '/root/.purple/pounces.xml': No such file or directory
Session Management: ICE initialized.
Session Management: Connecting with no previous ID
Session Management: Connection failed with error: Authentication Rejected, reason : None of the authentication protocols specified are supported and host-based authentication failed
account: Connecting to account abc
docklet: embedded
network: Entering nm_callback_func!
autorecon: do_signon called
autorecon: calling purple_account_connect
account: Connecting to account abc
autorecon: done calling purple_account_connect
util: Writing file accounts.xml to directory /root/.purple
util: Writing file blist.xml to directory /root/.purple
util: Writing file status.xml to directory /root/.purple
util: Writing file prefs.xml to directory /root/.purple
connection: Connecting. gc = 0x97b05a8
dns: DNS query for '192.168.113.15' queued
dns: Created new DNS child 3828, there are now 1 children.
dns: Successfully sent DNS request to child 3828
dns: Got response for '192.168.113.15'
dnsquery: IP resolved for 192.168.113.15
proxy: Attempting connection to 192.168.113.15
proxy: Connecting to scs.msg.yahoo.com:5050 via 192.168.113.15:8080 using HTTP
proxy: Connection in progress
proxy: Connected to scs.msg.yahoo.com:5050.
proxy: Using CONNECT tunneling for scs.msg.yahoo.com:5050
proxy: Proxy server replied with:
HTTP/1.1 502 Proxy Error ( The specified Secure Sockets Layer (SSL) port is not allowed. ISA Server is not configured to allow SSL requests from this port. Most Web browsers use port 443 for SSL requests. )
Via: 1.1 P1HISV01PX
Connection: close
Proxy-Connection: close
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html
Content-Length: 776
proxy: Connection attempt failed: HTTP proxy connection error 502
account: Disconnecting account 0x9449910
connection: Disconnecting connection 0x97b05a8
connection: Destroying connection 0x97b05a8
util: Writing file accounts.xml to directory /root/.purple
autorecon: do_signon called
autorecon: calling purple_account_connect
account: Connecting to account abc
connection: Connecting. gc = 0x9524270
dns: DNS query for '192.168.113.15' queued
autorecon: done calling purple_account_connect
dns: Created new DNS child 3831, there are now 1 children.
dns: Successfully sent DNS request to child 3831
dns: Got response for '192.168.113.15'
dnsquery: IP resolved for 192.168.113.15
proxy: Attempting connection to 192.168.113.15
proxy: Connecting to scs.msg.yahoo.com:5050 via 192.168.113.15:8080 using HTTP
proxy: Connection in progress
proxy: Connected to scs.msg.yahoo.com:5050.
proxy: Using CONNECT tunneling for scs.msg.yahoo.com:5050
proxy: Proxy server replied with:
HTTP/1.1 502 Proxy Error ( The specified Secure Sockets Layer (SSL) port is not allowed. ISA Server is not configured to allow SSL requests from this port. Most Web browsers use port 443 for SSL requests. )
Via: 1.1 P1HISV01PX
Connection: close
Proxy-Connection: close
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html
Content-Length: 776
proxy: Connection attempt failed: HTTP proxy connection error 502
account: Disconnecting account 0x9449910
connection: Disconnecting connection 0x9524270
connection: Destroying connection 0x9524270
util: Writing file accounts.xml to directory /root/.purple
prefs: /pidgin/blist/list_visible changed, scheduling save.
util: Writing file prefs.xml to directory /root/.purple
autorecon: do_signon called
autorecon: calling purple_account_connect
account: Connecting to account abc
connection: Connecting. gc = 0x951ff00
dns: DNS query for '192.168.113.15' queued
autorecon: done calling purple_account_connect
dns: Created new DNS child 3837, there are now 1 children.
dns: Successfully sent DNS request to child 3837
dns: Got response for '192.168.113.15'
dnsquery: IP resolved for 192.168.113.15
proxy: Attempting connection to 192.168.113.15
proxy: Connecting to scs.msg.yahoo.com:5050 via 192.168.113.15:8080 using HTTP
proxy: Connection in progress
proxy: Connected to scs.msg.yahoo.com:5050.
proxy: Using CONNECT tunneling for scs.msg.yahoo.com:5050
proxy: Proxy server replied with:
HTTP/1.1 502 Proxy Error ( The specified Secure Sockets Layer (SSL) port is not allowed. ISA Server is not configured to allow SSL requests from this port. Most Web browsers use port 443 for SSL requests. )
Via: 1.1 P1HISV01PX
Connection: close
Proxy-Connection: close
Pragma: no-cache
Cache-Control: no-cache
Content-Type: text/html
Content-Length: 776
proxy: Connection attempt failed: HTTP proxy connection error 502
account: Disconnecting account 0x9449910
connection: Disconnecting connection 0x951ff00
connection: Destroying connection 0x951ff00
util: Writing file accounts.xml to directory /root/.purple
 

proxy: Using CONNECT tunneling for scs.msg.yahoo.com:5050
proxy: Proxy server replied with:
HTTP/1.1 502 Proxy Error ( The specified Secure Sockets Layer (SSL) port is not allowed. ISA Server is not configured to allow SSL requests from this port. Most Web browsers use port 443 for SSL requests. )