TCPDUMP & counters - V5.0A on VAX V6.2

[Bryan Webb]

Folks,

I've got Multinet V5.0A-X running on a VAX with OpenVMS V6.2 (details
below) and a little situation has raised 3 questions:

1) How can the counters shown by MULTINET SHOW /STATISTICS be cleared
for any or all interfaces? (Do collisions sometimes show in the Output
Errors counter?)

2) Does MULTINET TCPDUMP inherently catch all packets hitting the
interface, or is another step required to put the interface into
promiscuous mode?

3) Is there any reason TCPDUMP on a VAX 6000-530 might not be able to
keep up with the flow of traffic on its old 10Mb/s Ethernet interface
(DEMNA)? At the moment, the system is mostly just hosting a few disks
for other nodes in the cluster over DSSI. (A recent tcpdump during some
heavy ftp activity had quite a number of entries that show as "[ttl 0]
but caused a netbsd host to complain about header length.)

Thanks!
--Bryan

[Michael Corbett]

Post by Bryan Webb
Folks,
I've got Multinet V5.0A-X running on a VAX with OpenVMS V6.2 (details
1) How can the counters shown by MULTINET SHOW /STATISTICS be cleared
for any or all interfaces? (Do collisions sometimes show in the Output
Errors counter?)

Not that I'm aware of.

Post by Bryan Webb
2) Does MULTINET TCPDUMP inherently catch all packets hitting the
interface, or is another step required to put the interface into
promiscuous mode?

No. By default it only captures packets destined for the
machine on interface se0. There is an undocumented /promiscuous
qualifier that will capture all traffic the interface sees.

Post by Bryan Webb
3) Is there any reason TCPDUMP on a VAX 6000-530 might not be able to
keep up with the flow of traffic on its old 10Mb/s Ethernet interface
(DEMNA)? At the moment, the system is mostly just hosting a few disks
for other nodes in the cluster over DSSI. (A recent tcpdump during some
heavy ftp activity had quite a number of entries that show as "[ttl 0]
but caused a netbsd host to complain about header length.)

There were a few issues with TCPDUMP in 5.0. Try the
following eco -

ftp://ftp.multinet.process.com/patches/multinet050/tcpdump-010_a050.zip

regards
Mike