????????????????????????????ù??????????ν?????裬????????е????????????????????й????????α?Linux????????????????????????????????????????????????????????????????????????????????????? Red Hat Linux?????????????????????????Щ?????Linux??α????????

??????????HTTP????

???????????Web????????????????????????????????????????磬Windows???IIS????HTTP??????Linux?г???????Apache.

????????Apache??????????κ???????????????????????????????????????????????????“Apache/1.3.27 Server at apache.Linuxforum.net Port 80”??“Apache/2.0.49(Unix) PHP/4.3.8”???????

??????????????????е? ServerTokens??????????? Apache???????????????????????RedHat Linux ???е? Apache ????????????????????????????????????Щ?????????Apache?????????????±??????????????滻?????????????

??????Apache 2.0.50???????ap_release.h????????“#defineAP_SERVER_BASEPRODUCT ”Apache“”?“#define AP_SERVER_BASEPRODUCT ”Mi-crosoft-IIS/5.0“”.??os/unix/os.h????????“#define PLATFORM ”Unix“”?“#define PLATFORM ”Win32“”.??????????±??????Apache.

????Apache ??????? ?? ???httpd.conf ?? ?? ?? ?? ?? ?? “ ServerTokens Full” ?? ?“ServerTokens Prod”;??“ServerSignature On”???“ServerSignature Off”????????????????????Apache???ù????????裬?????????????????????????Windows.

???????????FTP????

??????? FTP ???????????????????????????磬Windows ?μ? FTP ??????? Serv-U????Linux?3???vsftpd??proftpd??pureftpd???????

??????proftpd???????????????proftpd.conf??????????????

????ServerIdent on “Serv-U FTP Server v5.0 for WinSock ready…”

????????????????????proftpd??????????????????????FTP?????????в????

????C:>ftp 192.168.0.1
????Connected to 192.168.0.1.
????220 Serv-U FTP Server v5.0 for WinSock ready…
????User (192.168.0.1:(none))??
????331 Password required for (none)??
????Password:
????530 Login incorrect.
????Login failed.
????ftp > quit
????221 Goodbye.

???????????????????????????????????Serv-U??Windows???

???????????TTL?????

??????????ping?????????????????????TTL????????????????????????????????о????κ??????·??????磬??? ping??????????TTL?????????“TTL????”.?????У??????????????·??????TTL???1????TTL?0???????????????????

???????????￡?Windows??TTL???????128?????????Red Hat Linux??Solaris??TTL??????255??FreeBSD???°汾??Red Hat Linux??TTL??????64.???磬ping???Red Hat??????????￡?

????Pinging 192.168.0.1 with 32 bytes of data:
????Reply from 192.168.0.1: bytes=32 time <10ms TTL=64
????Reply from 192.168.0.1: bytes=32 time <10ms TTL=64
????Reply from 192.168.0.1: bytes=32 time <10ms TTL=64
????Reply from 192.168.0.1: bytes=32 time <10ms TTL=64
????Ping statistics for 192.168.0.1:
????Packets: Sent = 4?? Received = 4?? Lost = 0 (0% loss)??
????Approximate round trip times in milli-seconds:
????Minimum = 0ms?? Maximum = 0ms?? Average = 0ms

?????????????????Red Hat Linux??TTL?????128(?????64)??

????# echo 128 > /proc/sys/net/ipv4/ip_default_ttl