networking

traceroute response codes

2007-06-07

response meaning !H Host unreachable !N Network unreachable !P Protocol unreachable !S Source route not permitted !F Fragmentation needed but DF bit is set !X Communication administratively prohibited

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subnet/wildcard values

2007-06-07

CIDR SubnetMask WildcardMask HexSubNetMask 32 255.255.255.255 0.0.0.0 FF.FF.FF.FF 31 255.255.255.254 0.0.0.1 FF.FF.FF.FE 30 255.255.255.252 0.0.0.3 FF.FF.FF.FC 29 255.255.255.248 0.0.0.7 FF.FF.FF.F8 28 255.255.255.240 0.0.0.15 FF.FF.FF.F0 27 255.255.255.224 0.0.0.31 FF.FF.FF.E0 26 255.255.255.192 0.0.0.63 FF.FF.FF.C0 25 255.255.255.128 0.0.0.127 FF.FF.FF.80 24 255.255.255.0 0.0.0.255 FF.FF.FF.00 23 255.255.254.0 0.0.1.255 FF.FF.FE.00 22 255.255.252.0 0.0.3.255 FF.FF.FC.00 21 255.255.248.0 0.0.7.255 FF.FF.F8.00 20 255.255.240.0 0.0.15.255 [...]

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smtp response codes

2007-06-07

code meaning 211 System status or system help reply 214 Help message 220 Service ready 221 Service closing transmission channel 250 Requested mail action okay 251 User not local will forward to 252 Cannot VRFY user but will take message and attempt delivery 253 messages pending for node started 354 Start mail input end with [...]

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well known ports

2007-06-07

If you are planning to use one of the protocols on this list, consider it sufficiently “well-known” to indicate you should use the port assigned by IANA. Certain presumptions will be made on firewalls (hardware and client) and IDS systems regarding this traffic. The full list is maintained by the IANA and can be found [...]

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