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Diffstat (limited to 'package/iptables/files/l7/ntp.pat')
| -rw-r--r-- | package/iptables/files/l7/ntp.pat | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/package/iptables/files/l7/ntp.pat b/package/iptables/files/l7/ntp.pat new file mode 100644 index 0000000000..b7e443e21f --- /dev/null +++ b/package/iptables/files/l7/ntp.pat @@ -0,0 +1,17 @@ +# (S)NTP - (Simple) Network Time Protocol - RFCs 1305 and 2030 +# Pattern quality: good veryfast overmatch +# +# This pattern is tested and is believed to work. If this does not work +# for you, or you believe it could be improved, please post to +# l7-filter-developers@lists.sf.net . Subscribe at +# http://lists.sourceforge.net/lists/listinfo/l7-filter-developers + +# client|server +# Requires the server's timestamp to be in the present or future (of 2005). +# Tested with ntpdate on Linux. +# Assumes version 2, 3 or 4. + +# Note that ntp packets are always 48 bytes, so you should match on that too. + +ntp +^([\x13\x1b\x23\xd3\xdb\xe3]|[\x14\x1c$].......?.?.?.?.?.?.?.?.?[\xc6-\xff]) |