April 2004 - Test - lists.nanog.org

the value of reverse address lookups?
by Douglas F. Calvert 01 Apr '04

01 Apr '04

Hello, I am interested in finding out what the motivation is for requiring valid reverse address lookups before connecting to a daemon. I have heard a number of different explanations, the majority of the responses point to history/tradition and tcpwrappers. Is there a commonly accepted justification for this practice? In my opinion it does not appear to increase the validity of the connection. But I may be missing something obvious. Thanks in advance... --dfc returns to lurk mode Douglas F. Calvert

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RE: MLPPP Follow Up - How we fixed the problem
by jlewis＠lewis.org 01 Apr '04

01 Apr '04

On Thu, 1 Apr 2004, Paul Stewart wrote: > Any issues with more than 2 connections? We have a customer that we are > doing this for right now with two T1's.. Customer wants a third one > possibly.. Can't see a problem but thought I'd ask... > > How many could you theoretically do if you really had to? ;) AFAIK, depending on IOS version, the max-paths you can load balance with CEF is 6 or 8. i.e. In some older versions, it is 6, and I've had to do upgrades to get 8 T1's to load share. Most instances of this that I've done have been on our own network where we use OSPF on the T1's and set maximum-paths in router ospf. I have seen/done 4xT1 service load balanced to customers using static routes. ---------------------------------------------------------------------- Jon Lewis *jlewis(a)lewis.org*| I route Senior Network Engineer | therefore you are Atlantic Net | _________ http://www.lewis.org/~jlewis/pgp for PGP public key_________

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RE: Spam with no purpose?
by Michel Py 01 Apr '04

01 Apr '04

> Michael.Dillon(a)radianz.com wrote: > What would happen if an ISP's mail server were to collect > the URLs in emails and then retrieve the URL. Wouldn't > this create a lot of false positives for the spammer thus > screwing with their business model? It has to be smarter; this would not reproduce the decay rate, for example. Would fool only beginners. Michel.

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Re: Spam with no purpose?
by Michael.Dillon＠radianz.com 01 Apr '04

01 Apr '04

>A message like this will usualy contain an html portion with an image in it >that is a single pixel in size, that is white-on-white. It doesn't show up >when you look at it, but it sends a request to the sender's specified >website to get the pixel, thus showing them which email accounts are active. What would happen if an ISP's mail server were to collect the URLs in emails and then retrieve the URL. Wouldn't this create a lot of false positives for the spammer thus screwing with their business model? And what if some scumsucking bottom feeder were to create a whole bunch of fake email addresses pointing at the servers of ISPs who do this. And then this evil waste-of-space no-buts were to sell that list to spammers for a good price based on the fact that these were all good active email addresses? Criminals victimizing other criminals... oh what a surprise! And what if ISPs would get together and share the IP addresses of these 1-pixel web servers via some type of real-time feed so that they could engage in cooperative blocking of validation traffic? Would they be helping the spamming criminals or would they be helping the scamming criminals or would they be good guys?

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Doesn't appear to be a 'foolish' item..
by Robert Mathews 01 Apr '04

01 Apr '04

http://www.networksolutions.com/en_US/name-it/popup-100-yr-term.jhtml Robert. -------

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Is your domain licensed?
by Stephen J. Wilcox 01 Apr '04

01 Apr '04

Old news in terms of the granting of a patent on subdomains.. new news (afaik) that theyve now started sending out letters telling folks they need to pay now for a license: http://www.theregister.co.uk/content/4/36707.html Patent: http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/n… So, does anything need doing or like New.net and SCO do we just need to laugh at the futility and stupidity of these people and get back to more boring things? Steve

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RE: Spam with no purpose?
by Michel Py 01 Apr '04

01 Apr '04

>> Michel Py wrote: >> You can bet that it won't be long until we see such messages >> that not only use only dictionary words, but furthermore are >> constructed with a valid grammar (and still mean nothing). > William Leibzon wrote: > I already saw it. Right now its just random phrases being put > together and not yet entire text. And somewhere (actually > several years ago), I've read of AI program capable of creating > complete stories when its given some key phrases to start with, > would not be surprised if same or similar algorithms began to > be used. Mind forwarding a few? I believe that these are early probes though; no reason to kill the "bunch of dictionary words" technique too early. Michel.

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RE: Spam with no purpose?
by Michel Py 31 Mar '04

31 Mar '04

>> Deepak Jain wrote: >> Can someone explain to me (publicly or privately) why someone >> would send spam with no product to sell, no position to pitch, >> nothing except text designed to get by a spam filter -- >> without even HTML to KNOW it got by a spam filter.. > Gregory Hicks wrote > It is a probe to verify the address. since it did not > bounce, the address is verified. Old-school; nowadays probes to measure the real bounce rate are real text, not just a bunch of words. I got one recently thanking me for a wonderful week-end... Michel.

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MLPPP Follow Up - How we fixed the problem
by Richard J. Sears 31 Mar '04

31 Mar '04

I asked the group some time ago about some problems we were seeing with MLPPP on our Cisco 7513s. I have had 5 or 6 people contact me off list to ask how we solved the problem, so I figured I would post "our" solution to the group. I am sure there may be other fixes, however this works great for us and we have not had a problem in months since converting all MLPPP customers over. Basically we shut down MLPPP and went with (ip load-sharing per-packet) Here is what our config looks like: interface Serial1/0/0/13:0 description Customer #4144 (San Diego) #1 UPDATE [4144] ip address X.X.X.X 255.255.255.252 no ip directed-broadcast ip load-sharing per-packet ip route-cache distributed no cdp enable interface Serial2/1/0/14:0 description Customer #4144 (San Diego) #2 UPDATE [4144] ip address X.X.X.X 255.255.255.252 no ip directed-broadcast ip load-sharing per-packet ip route-cache distributed no cdp enable ip route X.X.X.X 255.255.255.252 Serial1/0/0/13:0 ip route X.X.X.X 255.255.255.252 Serial2/1/0/14:0 The only problem that we ran into was that we had to use the Serial designator of the interface in our route statement otherwise it will not work (or at least it did not for us). Since converting our customers (all MLPPP customers) to ip load-sharing per-packet - we have had no further problems. Hope this helps someone.... ****************************************** Richard J. Sears Vice President American Digital Network ---------------------------------------------------- rsears(a)adnc.com http://www.adnc.com ---------------------------------------------------- 858.576.4272 - Phone 858.427.2401 - Fax ---------------------------------------------------- I fly because it releases my mind from the tyranny of petty things . . "Work like you don't need the money, love like you've never been hurt and dance like you do when nobody's watching."

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Re: Spam with no purpose?
by Gregory Hicks 31 Mar '04

31 Mar '04

> Date: Wed, 31 Mar 2004 22:18:03 -0500 > From: Deepak Jain <deepak(a)ai.net> > To: nanog(a)merit.edu > Subject: Spam with no purpose? > > > > Can someone explain to me (publicly or privately) why someone would send > spam with no product to sell, no position to pitch, nothing except text > designed to get by a spam filter -- without even HTML to KNOW it got by > a spam filter.. It is a probe to verify the address. since it did not bounce, the address is verified. Some spam filters filter out empty messages. The words avoid this. Regards, Gregory Hicks > > For example: > > From: Joe Legitimate <jlegit(a)university.edu> > To: Deepak Jain <deepak(a)ai.net> > Subject: [dictionary word] > > [dictionary word] [dictionary word] [dictionary word] [dictionary word] > [dictionary word] [dictionary word] [dictionary word] [dictionary word] > [dictionary word] [dictionary word] [dictionary word] [dictionary word] > [dictionary word] [dictionary word] [dictionary word] [dictionary word] > [dictionary word] [dictionary word] [dictionary word] [dictionary word] > > --- EOM --- > > I don't understand why one would waste the time, if its a test, why > would it get out in public? > > I would like to think I am being naive, but I just don't see the upside > unless it were particularly targeted at me or my mailserver to determine > our response or response time, etc. > > Thanks in advance, > > DJ > --------------------------------------------------------------------- Gregory Hicks | Principal Systems Engineer Cadence Design Systems | Direct: 408.576.3609 555 River Oaks Pkwy M/S 6B1 | Fax: 408.894.3479 San Jose, CA 95134 | Internet: ghicks(a)cadence.com I am perfectly capable of learning from my mistakes. I will surely learn a great deal today. "A democracy is a sheep and two wolves deciding on what to have for lunch. Freedom is a well armed sheep contesting the results of the decision." - Benjamin Franklin "The best we can hope for concerning the people at large is that they be properly armed." --Alexander Hamilton

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