Re: TTL
At 9:14 PM -0800 2002/12/13, Jimi Thompson wrote: With the increasing complexity of the internet, this is often a problem for those who have large internal networks and/or live in Australia. 30 hops often isn't enough to make to the core DNS. It probably ought to be extended to something more realistic. The other numbers that I've seen used 64, 128, and 256. We ran into this problem in '96, when I was working at AOL. We had a guy in California who wanted to send e-mail to his friend across the hall, but of course those packets had to traverse the country to be delivered to our servers in Virginia. We went back and forth a few times, and I even set up tcpdump on the particular machine I told him to connect directly to -- I could see his packets coming in, but our responses were never received. Turns out that, by a quirk of routing fate, he was something like 32 hops away, and while his OS was fine, our particular patch revision of HP-UX 9 was hard-coded at 30. We applied a later patch to the machines, and everything went back to normal. This is not a new problem. Unfortunately, many OSes may still have inappropriate values defined. -- Brad Knowles, <[EMAIL PROTECTED]> "They that can give up essential liberty to obtain a little temporary safety deserve neither liberty nor safety." -Benjamin Franklin, Historical Review of Pennsylvania. GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI$ P+>++ L+ !E-(---) W+++(--) N+ !w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++) tv+(+++) b+() DI+() D+(++) G+() e++> h--- r---(+++)* z(+++) To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: TTL
On Fri, Dec 13, 2002 at 09:14:06PM -0800, Jimi Thompson wrote: > > > This is an issue that we recently ran into at work and I wanted to mention > this since 5.0 isn't released yet. I don't know if FreeBSD has addressed > this or not but thought it should be mentioned just in case. We've > discovered that in many *nix OS's the TCP stack sets the default TTL for > packets to 30. Apparently, IBM (AIX) had not and our research showed that > most of the other *nix OS's hadn't either. > > With the increasing complexity of the internet, this is often a problem for > those who have large internal networks and/or live in Australia. 30 hops > often isn't enough to make to the core DNS. It probably ought to be > extended to something more realistic. The other numbers that I've seen used > 64, 128, and 256. > troutmask:sgk[202] sysctl -a | grep -i ttl net.inet.ip.ttl: 64 -- Steve To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
Re: TTL
On Fri, Dec 13, 2002 at 09:14:06PM -0800, Jimi Thompson wrote: > > > This is an issue that we recently ran into at work and I wanted to mention > this since 5.0 isn't released yet. I don't know if FreeBSD has addressed > this or not but thought it should be mentioned just in case. We've > discovered that in many *nix OS's the TCP stack sets the default TTL for > packets to 30. Apparently, IBM (AIX) had not and our research showed that > most of the other *nix OS's hadn't either. > > With the increasing complexity of the internet, this is often a problem for > those who have large internal networks and/or live in Australia. 30 hops > often isn't enough to make to the core DNS. It probably ought to be > extended to something more realistic. The other numbers that I've seen used > 64, 128, and 256. I'm not completely sure but I believe the default TTL on 5.0 is 64. I've briefly tested this by pinging myself and watching the output, but if there are any special cases for that then I could very well be wrong. -- Ray Kohler <[EMAIL PROTECTED]> Those who do not understand Unix are condemned to reinvent it, poorly. -- Henry Spencer To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
TTL
This is an issue that we recently ran into at work and I wanted to mention this since 5.0 isn't released yet. I don't know if FreeBSD has addressed this or not but thought it should be mentioned just in case. We've discovered that in many *nix OS's the TCP stack sets the default TTL for packets to 30. Apparently, IBM (AIX) had not and our research showed that most of the other *nix OS's hadn't either. With the increasing complexity of the internet, this is often a problem for those who have large internal networks and/or live in Australia. 30 hops often isn't enough to make to the core DNS. It probably ought to be extended to something more realistic. The other numbers that I've seen used 64, 128, and 256. Thanks, Ms. Jimi Thompson Those who are too smart to engage in politics are punished by being governed by those who are dumber. - Plato To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
