Date: Sat, 17 May 2014 17:38:38 -0700 From: "Ronald F. Guilmette" <rfg@tristatelogic.com> To: freebsd-net@freebsd.org Subject: Re: Gateway? Message-ID: <73579.1400373518@server1.tristatelogic.com>
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Michael Sierchio kudzu at tenebras.com wrote: >On Sat, May 17, 2014 at 4:17 PM, Ronald F. Guilmette ><rfg at tristatelogic.com> wrote: > >> Quite simply, I'd like to know if the defaultrouter= IPv4 address >> specified in my /etc/rc.conf file should be the same as whatever >> I normally see as the first hop in an outgoing traceroute. > >Maybe... see comments below. > >> defaultrouter="69.62.255.254" >> >> and here is one example of a recent outgoing traceroute: >> >> % traceroute 74.125.239.148 >> traceroute to 74.125.239.148 (74.125.239.148), 64 hops max, 52 byte packets >> 1 86.255-62-69.res.dyn.surewest.net (69.62.255.86) 28.884 ms 31.395 ms 30.024 ms >> 2 216.0.55.209 (216.0.55.209) 26.486 ms 26.024 ms 25.850 ms > >Do you have a fixed IP address (statically assigned), Yes, I do. two of them in fact... 69.62.255.118 and 69.62.255.119. >or are you getting an address via DHCP from your ISP? No. I do use DHCP within my local network, but my connection(s) to my ISP are from my two static IPs. >If it's DHCP, your >defaultrouter definition is overridden every time you get/renew a lease. Right. Actually, I did know at least that much. >netstat -r -n -f inet | grep -v link > >tells where your packets go next. Yes, and my default route is definitely pointed at 69.62.255.254: ========================================================================== Routing tables Internet: Destination Gateway Flags Refs Use Netif Expire default 69.62.255.254 UGS 0 1615581 rl0 69.62.255.0/24 link#3 U 0 32 rl0 69.62.255.118 link#3 UHS 0 98 lo0 127.0.0.1 link#7 UH 0 18465739 lo0 192.168.1.0/24 link#4 U 0 7248 nfe0 192.168.1.2 link#4 UHS 0 0 lo0 ========================================================================== >But in any case, it's helpful to >know how traceroute works. It usually sends UDP packets with >increasing TTLs which are supposed to elicit an ICMP error message >(TTL expired) from hops along the way. I did actually know that much (but admittedly not much more). >The IP address you get a >response from may be different from what you expect, especially when >navigating the innards of your ISPs switch fabric. It's possible that >it isn't even the address of any interface on any router. If you could explain all of what you just said a bit more for me, I'm sure that it would be both enlightening and educational for me. (But if you don't have time, that's OK too. I understand that I should probably go buy a nice thick book or enroll in a two-semester course if I seriously wanted to understand this stuff in depth.) >On the intermittent failure issue - are you running a firewall? Yes. >Do you permit 67-68/udp between your gateway and the ISP? I'm not sure I underatand the question. The gateway machine belongs to the ISP. I do not have any control over which packets they allow to pass between one of their own machines and any other. Off list I'll send you output from "ipfw -a list" and you can tell me what you think. In general, traceroute _does_ appear to work OK on this system. >And did Surewest get acquired by XO? No, a company called "Consolidated Communications": http://www.consolidated.com/ (It used to be that when I would call tech support for Surewest, formerly Roseville Telephone... a little tiny island of helpful friendliness bounded on all sides by a veritable sea of PacBell unhelpfulness... I could actually talk to somebody local here in Roseville who actually knew something about networking... even when I called on the weekends. Today however, when I called tech support the first level ``support'' girl... yes, I'm sexist, and I said ``girl''... told me that she was located in Florida, and she quite clearly knew absolutely nothing about nothing, so I asked to speak to a second level person. This time it was a guy, who said he was in Texas, and he also quite clearly knew absolutely nothing. The only even vaguely useful thing he told me was that he ran some test on my line and the result came back at 9.6, which he said was borderline, adding that a really good number would be between 15 and 20. When I asked him to what these numbers referred, and what they were measurements of, he confessed that he had no idea, adding that "I'm not an engineer." Geeezzzz Louise! This caged monkey was looking at numbers and giving out numbers, and he doesn't even have the vaguest idea what they even mean or what they measure! Oh well, neither do I. But then again I'm not being *paid* to do ISP tech support. Geeezzzzzzz! Well, so he said that he'd open a ticket and send a trouble request to some "other department"... presumably the people who actually do know something about ISP operations... and then, after making me wait another 20 minutes on hold, he FINALLY gave me the trouble ticket number I had insisted upon obtaining. In short, things have definitely gone downhill in a big way. I'm just about ready to chuck it all and jump into the open arms of the Last Mile Evil Empire, aka Comcast.)
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