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Routing TCP/IP, Volume I (CCIE Professional Development) by Jeff Doyle

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Keyword Alternatives

Most networking professionals know some of the more commonly used TCP port numbers, and maybe a few UDP port numbers. Fewer could say what the ICMP type is for a ping or a destination unreachable, much less what the ICMP codes are for destination unreachable types. Beginning with IOS 10.3, access lists can be configured with keywords in place of many port, type, or code numbers. Using keywords, the access lists 110 and 111 from Figure B.10 are:

access-list 110 permit tcp any 172.22.0.0 0.0.255.255 establishedaccess-list 110 permit tcp any host 172.22.15.83 eq smtpaccess-list 110 permit tcp 10.0.0.0 0.255.255.255 172.22.114.0 0.0.0.255 eq telnetaccess-list 110 permit udp 10.64.32.0 0.0.0.255 host 172.22.15.87 eq tftpaccess-list 110 permit udp any host 172.22.15.85 eq domain ...

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