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LFS211 Lab 4.1

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fsierra
fsierra Posts: 3
edited June 9 in LFS211 Class Forum

the Lab instructs to use:
# tcpdump -i lo proto ICMP

If localhost is getting resolved to IPv6 (::1), tcpdump won't show any traffic
Following has to be used instead:
# tcpdump -i lo icmp6

using proto, or uppercase results in an error:

$ sudo tcpdump -i lo proto ICMP6
tcpdump: unknown ip proto 'ICMP6'

$ sudo tcpdump -i lo proto icmp6
tcpdump: can't parse filter expression: syntax error

Tested on Debian 12, tcpdump version 4.99.3, libpcap version 1.10.3 (with TPACKET_V3)

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