Visit The New, Modern Unix Linux Community

Linux and UNIX Man Pages

Test Your Knowledge in Computers #411
Difficulty: Medium
Aside from its AT&T UNIX base, XENIX incorporated elements from BSD, notably the vi text editor and its supporting libraries (termcap and curses).
True or False?
Linux & Unix Commands - Search Man Pages

ip-tunnel(8) [centos man page]

IP-TUNNEL(8)							       Linux							      IP-TUNNEL(8)

NAME
ip-tunnel - tunnel configuration SYNOPSIS
ip [ OPTIONS ] tunnel { COMMAND | help } ip tunnel { add | change | del | show | prl } [ NAME ] [ mode MODE ] [ remote ADDR ] [ local ADDR ] [ [i|o]seq ] [ [i|o]key KEY ] [ [i|o]csum ] ] [ encaplimit ELIM ] [ ttl TTL ] [ tos TOS ] [ flowlabel FLOWLABEL ] [ prl-default ADDR ] [ prl-nodefault ADDR ] [ prl-delete ADDR ] [ [no]pmtudisc ] [ dev PHYS_DEV ] MODE := { ipip | gre | sit | isatap | ip6ip6 | ipip6 | any } ADDR := { IP_ADDRESS | any } TOS := { STRING | 00..ff | inherit | inherit/STRING | inherit/00..ff } ELIM := { none | 0..255 } TTL := { 1..255 | inherit } KEY := { DOTTED_QUAD | NUMBER } TIME := NUMBER[s|ms] DESCRIPTION
tunnel objects are tunnels, encapsulating packets in IP packets and then sending them over the IP infrastructure. The encapsulating (or outer) address family is specified by the -f option. The default is IPv4. ip tunnel add add a new tunnel ip tunnel change change an existing tunnel ip tunnel delete destroy a tunnel name NAME (default) select the tunnel device name. mode MODE set the tunnel mode. Available modes depend on the encapsulating address family. Modes for IPv4 encapsulation available: ipip, sit, isatap and gre. Modes for IPv6 encapsulation available: ip6ip6, ipip6 and any. remote ADDRESS set the remote endpoint of the tunnel. local ADDRESS set the fixed local address for tunneled packets. It must be an address on another interface of this host. ttl N set a fixed TTL N on tunneled packets. N is a number in the range 1--255. 0 is a special value meaning that packets inherit the TTL value. The default value for IPv4 tunnels is: inherit. The default value for IPv6 tunnels is: 64. tos T dsfield T tclass T set the type of service (IPv4) or traffic class (IPv6) field on tunneled packets, which can be specified as either a two- digit hex value (e.g. c0) or a predefined string (e.g. internet). The value inherit causes the field to be copied from the original IP header. The values inherit/STRING or inherit/00..ff will set the field to STRING or 00..ff when tunneling non-IP packets. The default value is 00. dev NAME bind the tunnel to the device NAME so that tunneled packets will only be routed via this device and will not be able to escape to another device when the route to endpoint changes. nopmtudisc disable Path MTU Discovery on this tunnel. It is enabled by default. Note that a fixed ttl is incompatible with this option: tunneling with a fixed ttl always makes pmtu discovery. key K ikey K okey K ( only GRE tunnels ) use keyed GRE with key K. K is either a number or an IP address-like dotted quad. The key parameter sets the key to use in both directions. The ikey and okey parameters set different keys for input and output. csum, icsum, ocsum ( only GRE tunnels ) generate/require checksums for tunneled packets. The ocsum flag calculates checksums for outgoing pack- ets. The icsum flag requires that all input packets have the correct checksum. The csum flag is equivalent to the combina- tion icsum ocsum. seq, iseq, oseq ( only GRE tunnels ) serialize packets. The oseq flag enables sequencing of outgoing packets. The iseq flag requires that all input packets are serialized. The seq flag is equivalent to the combination iseq oseq. It isn't work. Don't use it. encaplim ELIM ( only IPv6 tunnels ) set a fixed encapsulation limit. Default is 4. flowlabel FLOWLABEL ( only IPv6 tunnels ) set a fixed flowlabel. ip tunnel prl potential router list (ISATAP only) dev NAME mandatory device name. prl-default ADDR prl-nodefault ADDR prl-delete ADDR Add or delete ADDR as a potential router or default router. ip tunnel show list tunnels This command has no arguments. SEE ALSO
ip(8) AUTHOR
Original Manpage by Michail Litvak <mci@owl.openwall.com> iproute2 20 Dec 2011 IP-TUNNEL(8)

Featured Tech Videos