iptraf-ng

IPTraf-ng is a console-based network monitoring utility.  IPTraf gathers
data like TCP connection packet and byte counts, interface statistics
and activity indicators, TCP/UDP traffic breakdowns, and LAN station
packet and byte counts.  IPTraf-ng features include an IP traffic monitor
which shows TCP flag information, packet and byte counts, ICMP
details, OSPF packet types, and oversized IP packet warnings;
interface statistics showing IP, TCP, UDP, ICMP, non-IP and other IP
packet counts, IP checksum errors, interface activity and packet size
counts; a TCP and UDP service monitor showing counts of incoming and
outgoing packets for common TCP and UDP application ports, a LAN
statistics module that discovers active hosts and displays statistics
about their activity; TCP, UDP and other protocol display filters so
you can view just the traffic you want; logging; support for Ethernet,
FDDI, ISDN, SLIP, PPP, and loopback interfaces; and utilization of the
built-in raw socket interface of the Linux kernel, so it can be used
on a wide variety of supported network cards.