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QRadar: 接続問題のトラブルシューティングのための SSH のデバッグ・モード有効化について

Troubleshooting


Problem

 QRadar は SSH 接続を使用して、コンソールと管理対象ホスト間で通信を行います。暗号化により、 Qradar は SSH 接続経由で暗号化されていないサービスへトンネリングすることが出来ます。この項目では、コンソールと管理対象ホスト間の SSH 問題を特定し、 SSH デバッグを有効にする方法について説明します。

Symptom

コンソールから管理対象ホストへの SSH 接続の確立を試行するが、以下のエラーが発生し失敗します。

[root@Console-1 ~]# ssh 192.0.2.11 22
ssh: connect to host 192.0.2.11 port 22: No route to host
ssh: connect to host 192.0.2.11 port 22: Connection timed out.
ssh: connect to host 192.0.2.11 port 22: Connection refused

Cause

 SSH セッションが確立できなかった要因として、以下のようないくつかの問題があります。

  • ホストのポート 22 がファイアウォールによりブロッキングされている。
  • ホストが稼働していない。
  • ホストは稼働しているが、 NIC に問題がある。 ( IP アドレスの構成が間違っている、 NIC ダウンなど)
  • ネットワーク構成の問題が原因でホストに到達できない。(例: ルーティングなど)
  • ホストは稼働しているが、 SSH サービスが動作していない。
  • ホストが稼働していて、 SSH も動作しているが、 SSH ネゴシエーションに失敗している。(例: SSH キーの不一致など)

Diagnosing The Problem

 SSH デバッグを有効にするには、 -v 、 -vv 、または -vvv オプションを指定して SSH コマンドを実行します。
以下の例では、ホスト間との通信のやり取りが完了するまでの SSH 接続がどのように成功するか確認できます。

[root@Con731-primary ~]# ssh -vvv 9.55.216.115
OpenSSH_7.4p1, OpenSSL 1.0.2k-fips  26 Jan 2017
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 58: Applying options for *
debug2: resolving "9.55.216.115" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to 9.55.216.115 [9.55.216.115] 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_7.4
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.4
debug1: match: OpenSSH_7.4 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 9.55.216.115:22 as 'root'
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /root/.ssh/known_hosts:9
debug3: load_hostkeys: loaded 1 keys from 9.55.216.115
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1,ext-info-c
debug2: host key algorithms: ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-ed25519-cert-v01@openssh.com,ssh-rsa-cert-v01@openssh.com,ssh-dss-cert-v01@openssh.com,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa,ssh-dss
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128-ctr,aes192-ctr,aes256-ctr,aes128-gcm@openssh.com,aes256-gcm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-64@openssh.com,umac-128@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,zlib@openssh.com,zlib
debug2: compression stoc: none,zlib@openssh.com,zlib
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256,curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp256,ssh-ed25519
debug2: ciphers ctos: aes128-ctr,aes192-ctr,aes256-ctr
debug2: ciphers stoc: aes128-ctr,aes192-ctr,aes256-ctr
debug2: MACs ctos: hmac-sha1,hmac-ripemd160
debug2: MACs stoc: hmac-sha1,hmac-ripemd160
debug2: compression ctos: none,zlib@openssh.com
debug2: compression stoc: none,zlib@openssh.com
debug2: languages ctos: 
debug2: languages stoc: 
debug2: first_kex_follows 0 
debug2: reserved 0 
debug1: kex: algorithm: curve25519-sha256
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha1 compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha1 compression: none
debug1: kex: curve25519-sha256 need=20 dh_need=20
debug1: kex: curve25519-sha256 need=20 dh_need=20
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp256 SHA256:vWG8e6abBrJqI5TvY3/adO9EVUwRWcAgQuzitwZD9UI
debug3: hostkeys_foreach: reading file "/root/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /root/.ssh/known_hosts:9
debug3: load_hostkeys: loaded 1 keys from 9.55.216.115
debug1: Host '9.55.216.115' is known and matches the ECDSA host key.
debug1: Found key in /root/.ssh/known_hosts:9
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 4294967296 blocks
debug2: key: /root/.ssh/id_rsa (0x5650ae27d730)
debug2: key: /root/.ssh/id_dsa ((nil))
debug2: key: /root/.ssh/id_ecdsa ((nil))
debug2: key: /root/.ssh/id_ed25519 ((nil))
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
debug3: preferred gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive,password
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
debug3: send packet: type 50
debug2: we sent a publickey packet, wait for reply
debug3: receive packet: type 60
debug1: Server accepts key: pkalg rsa-sha2-512 blen 535
debug2: input_userauth_pk_ok: fp SHA256:msozjuTd7R/Ma1EsbsaYBo6Kmt7hXbseDnWxPTAOyzA
debug3: sign_and_send_pubkey: RSA SHA256:msozjuTd7R/Ma1EsbsaYBo6Kmt7hXbseDnWxPTAOyzA
debug3: send packet: type 50
debug3: receive packet: type 52
debug1: Authentication succeeded (publickey).
Authenticated to 9.55.216.115 ([9.55.216.115]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting no-more-sessions@openssh.com
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: receive packet: type 80
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug3: receive packet: type 91
debug2: callback start
debug2: fd 3 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug3: send packet: type 98
debug1: Sending environment.
debug3: Ignored env XDG_SESSION_ID
debug3: Ignored env HOSTNAME
debug3: Ignored env TERM
debug3: Ignored env SHELL
debug3: Ignored env HISTSIZE
debug3: Ignored env SSH_CLIENT
debug3: Ignored env MIBDIRS
debug3: Ignored env SSH_TTY
debug3: Ignored env USER
debug3: Ignored env LS_COLORS
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: send packet: type 98
debug3: Ignored env PS1
debug3: Ignored env HISTCONTROL
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env NVA_CONF
debug3: Ignored env LOGNAME
debug3: Ignored env SSH_CONNECTION
debug3: Ignored env LESSOPEN
debug3: Ignored env XDG_RUNTIME_DIR
debug3: Ignored env IMQ_JAVAHOME
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0
Last login: Mon Sep  2 00:49:46 2019 from 9.55.216.114

Resolving The Problem

 SSH メッセージ・スタックが中断される場所に基づいて、問題を特定し調査することができます。

 ssh -v フラグによって障害が発生した箇所を解釈するための構成:

  •  ssh -v: 管理者(コンソール)側のメッセージを表示します。
  •  ssh -vv: 管理者(コンソール)側とホスト側の簡易的なメッセージを表示します。
  •  ssh -vvv: 管理者(コンソール)側とホスト側のほぼ全てのメッセージを表示します。

プロンプト:

  •  debug1: 管理者(コンソール)側の情報
  •  debug2: ホスト側の情報
  •  debug3: 管理者とホスト、およびそれ以外の情報

最初に SSH 接続が成功する時:

以下の例では、最初に SSH 接続を試行してどのように成功するか確認できます。最初の接続で RSA キーを受け入れるようにプロンプトが出力されます。

[root@Console-1]# ssh 192.0.2.11
The authenticity of host '192.0.2.11 (192.0.2.11)' can't be established.
RSA key fingerprint is bd:36:16:a8:00:2a:c9:56:6d:e2:26:eb:8d:66:3f:d5.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '192.0.2.11' (RSA) to the list of known hosts.
This server was upgraded to QRadar 7.2.6.20151107134559 on Thu Apr 14 21:42:58 EDT 2016.

 SSH 接続問題の詳細については、技術情報 10960602 をご参照ください。 - QRadar: Troubleshooting SSH connections and tunnels issues

Document Location

Worldwide

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Document Information

Modified date:
07 April 2020

UID

ibm11075239

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