Date: 25 Oct 2001 09:48:02 -0400 From: Lowell Gilbert <lowell@world.std.com> To: freebsd-questions@freebsd.org Subject: Re: Openssh Message-ID: <44ofmvu8z1.fsf@lowellg.ne.mediaone.net> In-Reply-To: sudz@ns3g.com's message of "Thu, 25 Oct 2001 12:55:08 %2B0000 (UTC)" References: <EGEAJNBPMIDPDNBOENHFIEICCLAA.sudz@ns3g.com> <EGEAJNBPMIDPDNBOENHFOEIECLAA.sudz@ns3g.com>
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sudz@ns3g.com (Colin Legendre) writes: > I have now noticed that this only occurs if you run trafshow/or/tcpdump on > the machine you are connected to, if you run trafshow on the server end the > connection it goes crazy, if you run it only on the client end it is fine. > Looks like there is a problem in the interaction between the ssh2 protocol > in Openssh and the bpf0 device. Any ideas? Maybe I'm misunderstanding your description, but it sounds like you're passing the output of tcpdump back through the ssh connection. That results in more traffic, because the tcpdump output itself becomes part of the traffic, which is picked up by tcpdump, which prints it out and puts it into the traffic, ad infinitum (until you hit your bandwidth limit or the bpf has to drop some traffic to keep up). I'd expect this cycle for this case; the question is really why it *doesn't* happen in the other protocol. But probably I *am* misunderstanding, and with luck you can just explain where I'm confused... > Colin Legendre CCNA, MCP > sudz@ns3g.com > http://www.ns3g.com > > -----Original Message----- > From: owner-freebsd-questions@FreeBSD.ORG > [mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Colin Legendre > Sent: Thursday, October 25, 2001 8:11 AM > To: freebsd-stable@FreeBSD.ORG; freebsd-questions@FreeBSD.ORG > Subject: Openssh > > > I have noticed something odd with the version of openssh on the stable > version of freebsd(Version OpenSSH_2.9 FreeBSD localisations 20010713, SSH > protocols 1.5/2.0, OpenSSL 0x0090601f). > > When using ssh1 not prob all good, but when I use ssh2(ie ssh -2 hostname) > and then run trafshow or tcpdump I noticed a crazy amount of traffic > generated, ie a constant flow of 40-50K per sec or more just by the ssh > session, yet under ssh1 it only gen's about 1-3K per sec. > > I tried this on an older version of ssh and this does not re-occur. Can > someone else try this and tell me what you get....ie > > ssh from any box to a FreeBSD4.4 stable box using ssh -2 hostname. Then do > a 'trafshow port 22' and see what your bytes/sec is after a 1min run or so. > > >From what I can tell it is a problem with sshd not the client. > > Thanks. > > > Colin Legendre CCNA, MCP > sudz@ns3g.com > http://www.ns3g.com > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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