100바이트가 넘는 데이터를 화면에 인쇄하면 VPNC를 통한 SSH 연결이 끊어집니다.

100바이트가 넘는 데이터를 화면에 인쇄하면 VPNC를 통한 SSH 연결이 끊어집니다.

기본 구성으로 VPN 연결이 있습니다.

IPSec gateway www.example.com
IPSec ID test
IPSec secret test
Xauth username foo
Xauth password bar

사용하고 sudo vpnc있는데 연결은 잘 됩니다. SSH를 통해 호스트에 연결하면 디렉터리 목록을 나열하고, 작은 파일, scp 작은 파일을 볼 수 있지만, 큰 파일이거나 콘솔에 대한 에코가 100바이트를 초과하면 연결이 멈추고 터미널을 종료해야 합니다. ssh를 다시 실행하세요(VPNC를 다시 시작할 필요가 없습니다).

문제를 해결하는 데 도움이 필요합니다. 저는 MacBook Yosemite 10.10.5에서 WiFi를 통해 Debian Jessie 8.6 VM을 실행하고 있습니다.

참고: VPN이 아닌 다른 사이트에 대한 다른 SSH 명령은 문제 없이 작동합니다. 동일한 Wi-Fi 및 Debian VM을 통해 로컬 서브넷에 SSH로 연결합니다.

내 연결 로그는 다음과 같습니다(보안을 위해 호스트 이름과 IP가 변경됨).

root@debJessie01:/etc/vpnc# vpnc example.conf 
VPNC started in background (pid: 14921)...
root@debJessie01:/etc/vpnc# ssh -vvvv [email protected]
OpenSSH_6.7p1 Debian-5+deb8u3, OpenSSL 1.0.1t  3 May 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to 192.168.1.1 [192.168.1.1] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/id_rsa type 1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /root/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.7p1 Debian-5+deb8u3
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.3
debug1: match: OpenSSH_5.3 pat OpenSSH_5* compat 0x0c000000
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "192.168.1.1" from file "/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /root/.ssh/known_hosts:3
debug3: load_hostkeys: loaded 1 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],ssh-rsa
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: [email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: [email protected],[email protected],ssh-rsa,[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],[email protected],arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected],[email protected],arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1,[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1,[email protected],[email protected],[email protected],[email protected],hmac-md5,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: none,[email protected],zlib
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: kex_parse_kexinit: diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,[email protected]
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,[email protected],hmac-sha2-256,hmac-sha2-512,hmac-ripemd160,[email protected],hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: none,[email protected]
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: 
debug2: kex_parse_kexinit: first_kex_follows 0 
debug2: kex_parse_kexinit: reserved 0 
debug2: mac_setup: setup [email protected]
debug1: kex: server->client aes128-ctr [email protected] none
debug2: mac_setup: setup [email protected]
debug1: kex: client->server aes128-ctr [email protected] none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<3072<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: bits set: 1531/3072
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 29:f5:f9:04:e8:15:33:be:16:9c:ab:38:44:bf:79:df
debug3: load_hostkeys: loading entries for host "192.168.1.1" from file "/root/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /root/.ssh/known_hosts:3
debug3: load_hostkeys: loaded 1 keys
debug1: Host '192.168.1.1' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:3
debug2: bits set: 1553/3072
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /root/.ssh/id_rsa (0x7f61450839f0),
debug2: key: /root/.ssh/id_dsa ((nil)),
debug2: key: /root/.ssh/id_ecdsa ((nil)),
debug2: key: /root/.ssh/id_ed25519 ((nil)),
debug1: Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password
debug3: start over, passed a different list publickey,gssapi-keyex,gssapi-with-mic,password
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_lookup gssapi-keyex
debug3: remaining preferred: gssapi-with-mic,publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-keyex
debug1: Next authentication method: gssapi-keyex
debug1: No valid Key exchange context
debug2: we did not send a packet, disable method
debug3: authmethod_lookup gssapi-with-mic
debug3: remaining preferred: publickey,keyboard-interactive,password
debug3: authmethod_is_enabled gssapi-with-mic
debug1: Next authentication method: gssapi-with-mic
debug1: Unspecified GSS failure.  Minor code may provide more information
No Kerberos credentials available

debug1: Unspecified GSS failure.  Minor code may provide more information
No Kerberos credentials available

debug1: Unspecified GSS failure.  Minor code may provide more information


debug1: Unspecified GSS failure.  Minor code may provide more information
No Kerberos credentials available

debug2: we did not send a packet, disable method
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /root/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-rsa blen 279
debug2: input_userauth_pk_ok: fp 2b:cd:74:d5:0e:ed:09:54:e4:ed:41:7b:23:7a:6e:3e
debug3: sign_and_send_pubkey: RSA 2b:cd:74:d5:0e:ed:09:54:e4:ed:41:7b:23:7a:6e:3e
debug1: Authentication succeeded (publickey).
Authenticated to 192.168.1.1 ([192.168.1.1]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug2: callback start
debug2: fd 3 setting TCP_NODELAY
debug3: packet_set_tos: set IP_TOS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug1: Sending environment.
debug3: Ignored env XDG_SESSION_ID
debug3: Ignored env SHELL
debug3: Ignored env TERM
debug3: Ignored env DERBY_HOME
debug3: Ignored env USER
debug3: Ignored env MAIL
debug3: Ignored env PATH
debug3: Ignored env PWD
debug3: Ignored env JAVA_HOME
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env LOGNAME
debug3: Ignored env J2SDKDIR
debug3: Ignored env J2REDIR
debug3: Ignored env _
debug3: Ignored env OLDPWD
debug2: channel 0: request shell confirm 1
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0
[[email protected] ~]# 

less -S로그 파일 길이가 몇 메가바이트에 도달 하면 연결이 중단됩니다. 나는 tail -5잘 기록할 수 있고 몇 줄을 표시할 수 있습니다.

어떤 팁이 있나요? 어떤 SSH 구성을 사용해야 합니까?

추가 정보: VPN 사이트는 이웃 국가에 있습니다. 다른 사용자는 이 문제를 경험하지 않습니다(Microsoft 및 Cisco 제품 사용).

고마워하는!

답변1

MTU를 변경하면 문제가 해결되었습니다. 나는 무작위로 숫자를 골랐다. 어떤 스크립트에서도 영구적으로 변경하지 않았으며 지금은 CLI에서만 변경했습니다.

물론 ifconfig. 호출된 터널 구성을 확인한 tun0후 실행하세요.

ifconfig tun0 mtu 1290

이제 원하는 만큼 로그를 따라갈 수 있습니다.

감사합니다 @drewbenn

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