Hi All I need clarification on how https monitor works in relation to cipher list 1 .Does bigd uses some specific protocol for monitoring backend servers . Can bigd be forced to use specifc protocol like tls for health checks thanks

Bigd has the Openssl cipher list available to use for custom filters so you can specify connection strings for HTTPS to use with SSL and TLS. https://support.f5.com/kb/en-us/solutions/public/13000/100/sol13156.html Hope that helps.... if not ping back.

Thanks Nitass for your explanation . So if i use tmsh modify command to use change cipher list of the monitor to exclude ssl ciphers it would be like : tmsh ltm modify monitor https httpscustom cipher-list DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 For the 2 nd part if i got it right first i need to remove https monitor from pool then start running ssldump and alongside apply monitor again . Correct me if i am wrong . Thanks

HTTPS monitor question

17 Replies

Chase_Abbott
Employee
Dec 23, 2014
Bigd has the Openssl cipher list available to use for custom filters so you can specify connection strings for HTTPS to use with SSL and TLS.

https://support.f5.com/kb/en-us/solutions/public/13000/100/sol13156.html

Hope that helps.... if not ping back.

nitass

Employee

Dec 24, 2014

So the monitor cipher list is checked in server side context that is with tmm -serverciphers 'DEFAULT:+SHA:+3DES:+kEDH'

bigd uses openssl cipher library. you could use openssl ciphers (openssl ciphers DEFAULT:+SHA:+3DES:+kEDH -v) instead of tmm --serverciphers.

Also when i did ssl dump for the pool member LTM bigd sent version sslv3.1 or TLS1.0 to the backend server.

Should not LTM send TLS 1.2 first as this is the highest protocol it supports ?

i understand you do see clienthello version 3.1 because server does not support tls 1.2 (on the first connection, bigd sends clienthello version 3.3 but server responds version 3.1. so, bigd will send clienthello version 3.1 on the subsequent connection). to see it, you can remove https monitor, run ssldump and then re-assign the monitor to pool.

e.g.

 configuration

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm monitor https https
ltm monitor https https {
    adaptive disabled
    cipherlist DEFAULT:+SHA:+3DES:+kEDH
    compatibility enabled
    destination *:*
    interval 5
    ip-dscp 0
    send "GET /\r\n"
    time-until-up 0
    timeout 16
}
root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:443 {
            address 200.200.200.101
            session monitor-enabled
            state up
        }
    }
    monitor https
}

 trace

[root@ve11a:Active:In Sync] config  ssldump -Aed -nni 0.0 port 443
New TCP connection 1: 200.200.200.11(37012) <-> 200.200.200.101(443)
1 1  1419466427.8307 (0.0036)  C>SV3.1(512)  Handshake
      ClientHello
        Version 3.3
        random[32]=
          91 2f f5 8a 2d 96 6e ae 08 e8 69 7b 99 19 e1 9a
          61 1d bb 68 b2 ca 69 3e e0 e4 5b 49 60 6a 48 59

...snipped...

1 2  1419466427.8602 (0.0295)  S>CV3.1(81)  Handshake
      ServerHello
        Version 3.1
        random[32]=
          54 9b 53 0b c5 4e c9 c3 fd 1e c5 11 41 64 f2 b2
          12 63 01 46 94 60 20 56 bb 66 fa d7 ef 54 8d e5
        session_id[32]=
          d8 e6 ba 14 36 0e 43 ce 07 41 d6 19 3b b3 6d 6a
          11 f4 90 03 bb ec 0e 55 ef 27 21 e4 3c 47 2e 91
        cipherSuite         TLS_RSA_WITH_RC4_128_MD5
        compressionMethod                   NULL

...snipped...

New TCP connection 2: 200.200.200.11(37013) <-> 200.200.200.101(443)
2 1  1419466432.8379 (0.0024)  C>SV3.1(236)  Handshake
      ClientHello
        Version 3.1
        random[32]=
          0d 67 58 de 02 72 e0 fd 0e 46 47 41 4d 17 b3 52
          19 a7 c1 c3 6b cd 90 3e 93 ce f1 e2 f7 9c 8e f7
        resume [32]=
          d8 e6 ba 14 36 0e 43 ce 07 41 d6 19 3b b3 6d 6a
          11 f4 90 03 bb ec 0e 55 ef 27 21 e4 3c 47 2e 91

...snipped...

SynACk_128568
Cirrostratus
Dec 25, 2014
Thanks Nitass for your explanation . So if i use tmsh modify command to use change cipher list of the monitor to exclude ssl ciphers it would be like : tmsh ltm modify monitor https httpscustom cipher-list DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 For the 2 nd part if i got it right first i need to remove https monitor from pool then start running ssldump and alongside apply monitor again . Correct me if i am wrong . Thanks

nitass_89166

Noctilucent

Dec 24, 2014

So the monitor cipher list is checked in server side context that is with tmm -serverciphers 'DEFAULT:+SHA:+3DES:+kEDH'

bigd uses openssl cipher library. you could use openssl ciphers (openssl ciphers DEFAULT:+SHA:+3DES:+kEDH -v) instead of tmm --serverciphers.

Also when i did ssl dump for the pool member LTM bigd sent version sslv3.1 or TLS1.0 to the backend server.

Should not LTM send TLS 1.2 first as this is the highest protocol it supports ?

e.g.

 configuration

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm monitor https https
ltm monitor https https {
    adaptive disabled
    cipherlist DEFAULT:+SHA:+3DES:+kEDH
    compatibility enabled
    destination *:*
    interval 5
    ip-dscp 0
    send "GET /\r\n"
    time-until-up 0
    timeout 16
}
root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:443 {
            address 200.200.200.101
            session monitor-enabled
            state up
        }
    }
    monitor https
}

 trace

[root@ve11a:Active:In Sync] config  ssldump -Aed -nni 0.0 port 443
New TCP connection 1: 200.200.200.11(37012) <-> 200.200.200.101(443)
1 1  1419466427.8307 (0.0036)  C>SV3.1(512)  Handshake
      ClientHello
        Version 3.3
        random[32]=
          91 2f f5 8a 2d 96 6e ae 08 e8 69 7b 99 19 e1 9a
          61 1d bb 68 b2 ca 69 3e e0 e4 5b 49 60 6a 48 59

...snipped...

1 2  1419466427.8602 (0.0295)  S>CV3.1(81)  Handshake
      ServerHello
        Version 3.1
        random[32]=
          54 9b 53 0b c5 4e c9 c3 fd 1e c5 11 41 64 f2 b2
          12 63 01 46 94 60 20 56 bb 66 fa d7 ef 54 8d e5
        session_id[32]=
          d8 e6 ba 14 36 0e 43 ce 07 41 d6 19 3b b3 6d 6a
          11 f4 90 03 bb ec 0e 55 ef 27 21 e4 3c 47 2e 91
        cipherSuite         TLS_RSA_WITH_RC4_128_MD5
        compressionMethod                   NULL

...snipped...

New TCP connection 2: 200.200.200.11(37013) <-> 200.200.200.101(443)
2 1  1419466432.8379 (0.0024)  C>SV3.1(236)  Handshake
      ClientHello
        Version 3.1
        random[32]=
          0d 67 58 de 02 72 e0 fd 0e 46 47 41 4d 17 b3 52
          19 a7 c1 c3 6b cd 90 3e 93 ce f1 e2 f7 9c 8e f7
        resume [32]=
          d8 e6 ba 14 36 0e 43 ce 07 41 d6 19 3b b3 6d 6a
          11 f4 90 03 bb ec 0e 55 ef 27 21 e4 3c 47 2e 91

...snipped...

SynACk_128568
Cirrostratus
Dec 25, 2014
Thanks Nitass for your explanation . So if i use tmsh modify command to use change cipher list of the monitor to exclude ssl ciphers it would be like : tmsh ltm modify monitor https httpscustom cipher-list DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 For the 2 nd part if i got it right first i need to remove https monitor from pool then start running ssldump and alongside apply monitor again . Correct me if i am wrong . Thanks

nitass
Employee
Dec 25, 2014
tmsh ltm modify monitor https httpscustom cipher-list DEFAULT:+SHA:+3DES:+kEDH:!SSLv3

e.g.

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) modify ltm monitor https myhttps cipherlist DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm monitor https myhttps ltm monitor https myhttps { adaptive disabled cipherlist DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 compatibility enabled defaults-from https destination *:* interval 5 ip-dscp 0 send "GET /\r\n" time-until-up 0 timeout 16 } root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) q [root@ve11a:Active:In Sync] config ssldump -Aed -nni 0.0 host 200.200.200.101 and port 443 New TCP connection 1: 200.200.200.11(43738) <-> 200.200.200.101(443) 1 1 1419479022.6682 (0.0036) C>SV3.1(208) Handshake ClientHello Version 3.3 random[32]= 37 62 de 45 83 46 bc 86 aa 55 0c 6f 24 7a fd d2 64 fd 9b fd a4 f8 e2 3a aa 71 09 95 27 e7 9a c7

For the 2 nd part if i got it right first i need to remove https monitor from pool then start running ssldump and alongside apply monitor again

yes but if you use DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 cipher, you do not need to do it (i.e. remove and re-assign the monitor) because sslv3 is already removed.
- SynACk_128568
  Cirrostratus
  Dec 25, 2014
  Hi Nitass , One more thing output of this command : openssl ciphers DEFAULT:+SHA:+3DES:+kEDH -v AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 AES128-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA1 RC4-SHA SSLv3 Kx=RSA Au=RSA Enc=RC4(128) Mac=SHA1 DES-CBC3-SHA SSLv3 Kx=RSA Au=RSA Enc=3DES(168) Mac=SHA1 DHE-RSA-AES256-SHA SSLv3 Kx=DH Au=RSA Enc=AES(256) Mac=SHA1 DHE-DSS-AES256-SHA SSLv3 Kx=DH Au=DSS Enc=AES(256) Mac=SHA1 DHE-RSA-AES128-SHA SSLv3 Kx=DH Au=RSA Enc=AES(128) Mac=SHA1 DHE-DSS-AES128-SHA SSLv3 Kx=DH Au=DSS Enc=AES(128) Mac=SHA1 EDH-RSA-DES-CBC3-SHA SSLv3 Kx=DH Au=RSA Enc=3DES(168) Mac=SHA1 EDH-DSS-DES-CBC3-SHA SSLv3 Kx=DH Au=DSS Enc=3DES(168) Mac=SHA1 All are sslv3 ciphers but how is bigd using SSLv3.1/TLS 1.0 ? Also when using this command openssl ciphers DEFAULT:+SHA:+3DES:+kEDH:-SSLv3 -v Output is below no cipher left so this will cause the monitor to mark backend server down . Error in cipher list 4599:error:1410D0B9:SSL routines:SSL_CTX_set_cipher_list:no cipher match:ssl_lib.c:1188: Thanks
- nitass
  Employee
  Dec 25, 2014
  Protocol version: SSLv3, TLSv1.2. The TLSv1.0 ciphers are flagged with SSLv3. No new ciphers were added by TLSv1.1. https://www.openssl.org/docs/ssl/SSL_CIPHER_get_name.html
- SynACk_128568
  Cirrostratus
  Dec 25, 2014
  thanks A) But if i remove the remove sslv3 it will remove all the ciphers and health check will fail . So i dont think there is any way to negate sslv3 in monitor . Because when i negate sslv3 DEFAULT:+SHA:+3DES:+kEDH:-SSLv3 pool members go down as no ciphers are left as both are named same sslv3 and tls1.0 So my question is : B) Is there any tmsh command/way to disable SSLv3 protocol instead of SSLv3 ciphers in particular monitors and SSL profile ?
nitass_89166
Noctilucent
Dec 25, 2014
tmsh ltm modify monitor https httpscustom cipher-list DEFAULT:+SHA:+3DES:+kEDH:!SSLv3

e.g.

root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) modify ltm monitor https myhttps cipherlist DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) list ltm monitor https myhttps ltm monitor https myhttps { adaptive disabled cipherlist DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 compatibility enabled defaults-from https destination *:* interval 5 ip-dscp 0 send "GET /\r\n" time-until-up 0 timeout 16 } root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) root@(ve11a)(cfg-sync In Sync)(Active)(/Common)(tmos) q [root@ve11a:Active:In Sync] config ssldump -Aed -nni 0.0 host 200.200.200.101 and port 443 New TCP connection 1: 200.200.200.11(43738) <-> 200.200.200.101(443) 1 1 1419479022.6682 (0.0036) C>SV3.1(208) Handshake ClientHello Version 3.3 random[32]= 37 62 de 45 83 46 bc 86 aa 55 0c 6f 24 7a fd d2 64 fd 9b fd a4 f8 e2 3a aa 71 09 95 27 e7 9a c7

For the 2 nd part if i got it right first i need to remove https monitor from pool then start running ssldump and alongside apply monitor again

yes but if you use DEFAULT:+SHA:+3DES:+kEDH:!SSLv3 cipher, you do not need to do it (i.e. remove and re-assign the monitor) because sslv3 is already removed.
- SynACk_128568
  Cirrostratus
  Dec 25, 2014
  Hi Nitass , One more thing output of this command : openssl ciphers DEFAULT:+SHA:+3DES:+kEDH -v AES256-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(256) Mac=SHA1 AES128-SHA SSLv3 Kx=RSA Au=RSA Enc=AES(128) Mac=SHA1 RC4-SHA SSLv3 Kx=RSA Au=RSA Enc=RC4(128) Mac=SHA1 DES-CBC3-SHA SSLv3 Kx=RSA Au=RSA Enc=3DES(168) Mac=SHA1 DHE-RSA-AES256-SHA SSLv3 Kx=DH Au=RSA Enc=AES(256) Mac=SHA1 DHE-DSS-AES256-SHA SSLv3 Kx=DH Au=DSS Enc=AES(256) Mac=SHA1 DHE-RSA-AES128-SHA SSLv3 Kx=DH Au=RSA Enc=AES(128) Mac=SHA1 DHE-DSS-AES128-SHA SSLv3 Kx=DH Au=DSS Enc=AES(128) Mac=SHA1 EDH-RSA-DES-CBC3-SHA SSLv3 Kx=DH Au=RSA Enc=3DES(168) Mac=SHA1 EDH-DSS-DES-CBC3-SHA SSLv3 Kx=DH Au=DSS Enc=3DES(168) Mac=SHA1 All are sslv3 ciphers but how is bigd using SSLv3.1/TLS 1.0 ? Also when using this command openssl ciphers DEFAULT:+SHA:+3DES:+kEDH:-SSLv3 -v Output is below no cipher left so this will cause the monitor to mark backend server down . Error in cipher list 4599:error:1410D0B9:SSL routines:SSL_CTX_set_cipher_list:no cipher match:ssl_lib.c:1188: Thanks
- nitass_89166
  Noctilucent
  Dec 25, 2014
  Protocol version: SSLv3, TLSv1.2. The TLSv1.0 ciphers are flagged with SSLv3. No new ciphers were added by TLSv1.1. https://www.openssl.org/docs/ssl/SSL_CIPHER_get_name.html
- SynACk_128568
  Cirrostratus
  Dec 25, 2014
  thanks A) But if i remove the remove sslv3 it will remove all the ciphers and health check will fail . So i dont think there is any way to negate sslv3 in monitor . Because when i negate sslv3 DEFAULT:+SHA:+3DES:+kEDH:-SSLv3 pool members go down as no ciphers are left as both are named same sslv3 and tls1.0 So my question is : B) Is there any tmsh command/way to disable SSLv3 protocol instead of SSLv3 ciphers in particular monitors and SSL profile ?

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HTTPS monitor question

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