Options

-a

Do not display application layer data.

-b

Buffer standard output. Useful when you're redirecting output to a file.

-c cnt, --count cnt

Terminate after receiving cnt packets.

-C proto, --CCP proto

Assume a particular CCP protocol, such as MPPC. MPPC is the only one supported as yet.

-d

Dump extra padding in packets. For example, according to an IP header, the packet ends at a certain point, but the link layer may have padded it beyond that. This option displays the padding. Not valid in minimal mode.

-h, --help

Display usage screen with a brief description of the command line options.

-i if, --interface if

Makes ipgrab listen to packets on interface if, e.g., eth0. If this option is not used, the default interface will be assumed.

-l

Don't display link-layer headers. The following protocols are considered to be link layer: ARP, CHAP, Ethernet, IPCP, LCP, LLC, Loopback, PPP, PPPoE, Raw, Slip.

-m

Minimal mode output. When operating in this mode, ipgrab displays only brief header information.

-n

Don't display network-layer headers. The following protocols are considered to be network layer: AH, ESP, GRE, ICMP, ICMPv6, IGMP, IP, IPv6, IPX, IPXRIP.

-P string

Initiate a dynamic port mapping. This option must be followed by a string of the form `<protocol>=<port>', such as `http=8080'.

-p

Dump packet payloads beyond what IPgrab parses. In other words, if IPgrab does not parse a particular application, this option will dump application data in hex and text format.

-r FILE

Read packets from a file, rather than an interface. The file should be created in "raw" format, such as with '-w' option.

-T

Do not display timestamps in minimal mode.

-t

Don't display transport layer headers. The following protocols are considered to be transport layer: SPX, TCP, UDP.

-v, --version

Display version number and then quit.

-w FILE

Write the raw packets to a file, rather than the screen. The packets will not be parsed. The file can be read with the '-r' option.

-x

Hex dump mode. After processing each layer, dump out the contents of that layer in hex and text. Only valid in main mode.

expr

Berkeley packet filter expression. See tcpdump(8) man page for details and examples.