Re: Policy News
Command+0 for the activity viewer - then click on the stop sign Sent from my iPhone. Please execute spelling errors. On 18.11.2009, at 17:43, Steven Bellovin s...@cs.columbia.edu wrote: Does anyone know an easy way to do kill thread in MacOS's Mail.App? It's getting increasingly hard to read the NANOG list on my Mac without such a capability. (Yes, the question is serious on its own, apart from any other meanings you may choose to read into it.)
Re: Policy News
On 18.11.2009, at 20:08, Jeff Saxe wrote: I don't think Steve meant a way to stop the CPU / process thread of retrieving email if it is hung talking to an email server, although thank you for that. I believe Steve meant I want to keep reading the NANOG mailing list in general, but this particular message thread has zero interest to me, so as any new emails come in that are replies to replies to replies to this thread, just suppress them so I don't have to even hit Delete.. Something like that. Ah, I thought you meant threads were blocking Mail.app from processing messages in other mailboxes. I subscribe to several imap boxes with over half a million messages in them, so I use activity monitor to kill sync all the time. Mail.app seems to not process anything else on the same account as long as it's busy processing a subscription for a particular mailbox, which can take forever in some cases. As to the actual question, I use Mail.app in threaded mode anyway. When I'm not interested in a thread, I just let it collect messages and mark it as read every couple of days. I'm not aware of any way to tell Mail.app to quit showing messages from a particular thread. Chris
Re: OT: Voice Operators' Group forming
On 29.07.2009, at 22:52, Jason LeBlanc wrote: Brandon Butterworth wrote: NAVOG works for me. I'd prefer Voice Operators' Group Online Network brandon *claps* Imagine the poetry you have to listen to when _those_ guys put you on hold...
Re: In a bit of bind...
On 01.06.2009, at 12:59, Ben Matthew wrote: Finally I've managed to successfully configure BIND 9 as a slave to a myDNS server and the AXFR transfers seem to be working fine. This strikes me as being quite a nice balance of ease of use and reliability in case myDNS fails on me. Ok I appreciate it doesn't get around security concerns but hey ho. As far as as security, why have myDNS world-reachable at all? You can have bind feed off of myDNS without having anyone on the outside ever talk to the myDNS backend. Chris
two interfaces one subnet
Hi, This is a pretty moronic question, but I've been searching RFC's on- and-off for a couple of weeks and can't find an answer. So I'm hoping someone here will know it offhand. I've been looking through RFC's trying to find a clear statement that having two interfaces in the same subnet does not work, but can't find it that statement anywhere. The OS in this case is Linux. I know it can be done with clever routing and prioritization and such, but this has to do with vanilla config, just setting up two interfaces in one network. I would be grateful for a pointer to such an RFC statement, assuming it exists. Thanks! Chris
Re: two interfaces one subnet
On 11.05.2009, at 22:34, Patrick W. Gilmore wrote: On May 11, 2009, at 4:29 PM, Chris Meidinger wrote: I would be grateful for a pointer to such an RFC statement, assuming it exists. Why would an RFC prohibit this? Most _implementations_ do, but as far as network rules in general it is a valid configuration. That was essentially my conclusion as well: logically it can't work, but I wasn't certain where it might be forbidden. Thusly did I come to NANOG with the question, thinking smarter people than I might know. If it's completely down to implementation, or really to the interaction between TCP and underlying IP, then so be it. I was hoping that I might just not have thought of the right place to look. On 11.05.2009, at 22:39, Mikael Abrahamsson wrote: On Mon, 11 May 2009, Chris Meidinger wrote: I've been looking through RFC's trying to find a clear statement that having two interfaces in the same subnet does not work, but can't find it that statement anywhere. I don't know if it still works, but it did in Linux little over 10 years back. Proxy-arp:ed all the IPs in the /27 in the /24 and everything was fine (legacy reasons plus radiolink which I didn't want to run a lot of broadcasts over). There are legitimate cases where you might want to do this. Yes, I've gotten it to work as well as little as 10 days ago, but it's not something that $random_customer should be doing as a matter of practice. Thus, again, my hope that I just wasn't thinking of the right place to look to find an IETF recommendation against doing so. Thanks for the input! Chris
Re: two interfaces one subnet
On 11.05.2009, at 23:00, Charles Wyble wrote: What does two interfaces in one subnet mean? Two NICs? Or virtual interfaces? Two NICs, as in physical interfaces.
Re: two interfaces one subnet
On 11.05.2009, at 23:19, Alex H. Ryu wrote: Unless you configure Layer 2 for two interfaces, it's not going to work. It is invalid from networking principle. If you have to send the traffic for host in same subnet you configured, which interface it should send out ? Basically it may create broadcast storm loop by putting two ip addresses in same subnet in different interface. It may be allowed from host-level, but from router equipment, I don't think it was allowed at all. Alex, I _personally_ know that it's a problem. I was hoping for an RFC- reference, or similar standards document, to show to customers to convince them to stop trying to hack things to make it work. Chris
Re: two interfaces one subnet
On 11.05.2009, at 23:31, Dan White wrote: Chris Meidinger wrote: Hi, This is a pretty moronic question, but I've been searching RFC's on- and-off for a couple of weeks and can't find an answer. So I'm hoping someone here will know it offhand. I've been looking through RFC's trying to find a clear statement that having two interfaces in the same subnet does not work, but can't find it that statement anywhere. The OS in this case is Linux. I know it can be done with clever routing and prioritization and such, but this has to do with vanilla config, just setting up two interfaces in one network. I would be grateful for a pointer to such an RFC statement, assuming it exists. If your goal is to achieve redundancy or to increase bandwidth, you can bond the interfaces together - assuming that you have a switch / switch stack that supports 802.3ad. Then you could assign multiple IPs to the bonded interface without any layer 3 messyness. I should have been clearer. The case in point is having two physical interfaces, each with a unique IP, in the same subnet. For example, eth0 is 10.0.0.1/24 and eth1 is 10.0.0.2/24, nothing like bonding going on. The customers usually have the idea of running one interface for administration and another for production (which is a _good_ idea) but they want to do it in the same subnet (not such a good idea...) Chris
Re: two interfaces one subnet
On 11.05.2009, at 23:42, Kevin Oberman wrote: Date: Mon, 11 May 2009 16:19:56 -0500 From: Alex H. Ryu r.hyuns...@ieee.org Unless you configure Layer 2 for two interfaces, it's not going to work. It is invalid from networking principle. If you have to send the traffic for host in same subnet you configured, which interface it should send out ? Basically it may create broadcast storm loop by putting two ip addresses in same subnet in different interface. It may be allowed from host-level, but from router equipment, I don't think it was allowed at all. Alex I am a bit baffled as to why people think: 1. It won't work 2. It is a bad thing to do if it would work Neither is true. If it is two separate interfaces with two MAC addresses, it will work fine IF one of the interfaces is configured with a netmask of 255.255.255.255 (/32). Of course, you will have to add routes for the second interface if you expect to source traffic from it, but it really in not rare. This is, of course, how I've done it at times in the past. Routing management can, however, become quite a pain over time. The customer expectation is, naturally, that any traffic related to a connection that comes in to the first interface should go back out that interface, and anything related to a connection that came into the second interface should go back out there. (All this without any specific routing etc.) I think we both know that that's not going to happen automagically. Chris
Re: Why is www.google.cat resolving?
On 05.05.2009, at 09:33, Seth Mattinen wrote: Tim Tuppence wrote: Hello, I am seeing that www.google.cat resolves from three different networks. It even resolves from here: http://www.squish.net/dnscheck/ What is going on? Why are you expecting it not to? I think the real question here is why does schroedingers.cat not resolve, and who will be the first person able to jump through the requisite hoops make it do so.
Re: Network SLA
On 18.03.2009, at 12:20, Saqib Ilyas wrote: I'm back! Thanks again to all those who replied. I am wondering how a service provider might assess availability or reliability figures using active measurements. Granted that one could set up traffic generators between the two PoPs which will be connected to a customer's sites, and then after a day of test traffic, I can look for downtimes and restoration times. This is an exact description of IPSLA. Of course you don't know whether a maximum bandwidth was in fact available, because you don't want to saturate the link. But a one day estimate is not a good estimate for what the service provider is promising, which is usually maximum of 10 hours downtime in an year, is it not? You need a year of measurement. Thanks and best regards On Fri, Mar 13, 2009 at 7:34 PM, Athanasios Douitsis aduit...@gmail.com wrote: Anyone interested in setting up his own IP SLA probes by hand and then collect the measurements into a database, can use a Perl tool we developed at 2005: http://sourceforge.net/projects/saa-collector It's rather old (SAA got renamed into IPSLA in the meantime) and, in retrospect, the code is a little rough around the edges, but it's nevertheless usable. Regards, Athanasios On Wed, Mar 11, 2009 at 10:20 PM, Andreas, Rich rich_andr...@cable.comcast.com wrote: I have found that Cisco IPSLA is heavily used in the MSO/Service Provider Space. Juniper has equivalent functionality via RPM. Rich -Original Message- From: Saqib Ilyas [mailto:msa...@gmail.com] Sent: Saturday, March 07, 2009 6:12 AM To: nanog@nanog.org Subject: Re: Network SLA I must thank everyone who has answered my queries. Just a couple more short questions. For instance, if one is using MRTG, and wants to check if we can meet a 1 Mbps end-to-end throughput between a couple of customer sites, I believe you would need to use some traffic generator tools, because MRTG merely imports counters from routers and plots them. Is that correct? We've heard of the BRIX active measurement tool in replies to my earlier email. Also, I've found Cisco IP SLA that also sends traffic into the service provider network and measures performance. How many people really use IP SLA feature? Thanks and best regards On Mon, Feb 23, 2009 at 1:19 PM, Zartash Uzmi zart...@gmail.com wrote: As I gather, there is a mix of answers, ranging from building the resources according to requirements and HOPE for the best to use of arguably sophisticated tools and perhaps sharing the results with the legal department. I would be particularly interested in hearing the service providers' viewpoint on the following situation. Consider a service provider with MPLS deployed within its own network. (A) When the SP enters into a relation with the customer, does the SP establish new MPLS paths based on customer demands (this is perhaps similar to building based on requirements as pointed out by David)? If yes, between what sites/POPs? I assume the answer may be different depending upon a single-site customer or a customer with multiple sites. (B) For entering into the relationship for providing X units of bandwidth (to another site of same customer or to the Tier-1 backbone), does the SP use any wisdom (in addition to MRTG and the likes)? If so, what scientific parameters are kept in mind? (C) How does the customer figure out that a promise for X units of bandwidth is maintained by the SP? I believe customers may install some measuring tools but is that really the case in practice? Thanks, Zartash On Fri, Feb 20, 2009 at 1:16 AM, Stefan netfort...@gmail.com wrote: Saqib Ilyas wrote: Greetings I am curious to know about any tools/techniques that a service provider uses to assess an SLA before signing it. That is to say, how does an administrator know if he/she can meet what he is promising. Is it based on experience? Are there commonly used tools for this? Thanks and best regards Not necessarily as a direct answer (I am pretty sure there'll be others on this list giving details in the area of specific tools and standards), but I think this may be a question (especially considering your end result concern: *signing the SLA!) equally applicable to your legal department. In the environment we live, nowadays, the SLA could (should?!? ... unfortunately) be refined and (at the other end - i.e. receiving) interpreted by the lawyers, with possibly equal effects (mostly financial and as overall impact on the business) as the tools we (the technical people) would be using to measure latency, uptime, bandwidth, jitter, etc... Stefan -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences
Re: Network SLA
Saqib, On 07.03.2009, at 12:12, Saqib Ilyas wrote: I must thank everyone who has answered my queries. Just a couple more short questions. For instance, if one is using MRTG, and wants to check if we can meet a 1 Mbps end-to-end throughput between a couple of customer sites, I believe you would need to use some traffic generator tools, because MRTG merely imports counters from routers and plots them. Is that correct? Yes, if you want to do a test bandwidth, iperf should probably be your first stop. We've heard of the BRIX active measurement tool in replies to my earlier email. Also, I've found Cisco IP SLA that also sends traffic into the service provider network and measures performance. How many people really use IP SLA feature? I know a lot of people that use IPSLA. Remember, that you set it up between two routers or higher-end switches and it constantly tests that connection. However, IPSLA is the wrong tool for a one-off test of whether you can push a Mbps from site A to site B, because you need to saturate the link to do that test. IPSLA is great for monitoring things like jitter. HTH, Chris Thanks and best regards On Mon, Feb 23, 2009 at 1:19 PM, Zartash Uzmi zart...@gmail.com wrote: As I gather, there is a mix of answers, ranging from building the resources according to requirements and HOPE for the best to use of arguably sophisticated tools and perhaps sharing the results with the legal department. I would be particularly interested in hearing the service providers' viewpoint on the following situation. Consider a service provider with MPLS deployed within its own network. (A) When the SP enters into a relation with the customer, does the SP establish new MPLS paths based on customer demands (this is perhaps similar to building based on requirements as pointed out by David)? If yes, between what sites/POPs? I assume the answer may be different depending upon a single-site customer or a customer with multiple sites. (B) For entering into the relationship for providing X units of bandwidth (to another site of same customer or to the Tier-1 backbone), does the SP use any wisdom (in addition to MRTG and the likes)? If so, what scientific parameters are kept in mind? (C) How does the customer figure out that a promise for X units of bandwidth is maintained by the SP? I believe customers may install some measuring tools but is that really the case in practice? Thanks, Zartash On Fri, Feb 20, 2009 at 1:16 AM, Stefan netfort...@gmail.com wrote: Saqib Ilyas wrote: Greetings I am curious to know about any tools/techniques that a service provider uses to assess an SLA before signing it. That is to say, how does an administrator know if he/she can meet what he is promising. Is it based on experience? Are there commonly used tools for this? Thanks and best regards Not necessarily as a direct answer (I am pretty sure there'll be others on this list giving details in the area of specific tools and standards), but I think this may be a question (especially considering your end result concern: *signing the SLA!) equally applicable to your legal department. In the environment we live, nowadays, the SLA could (should?!? ... unfortunately) be refined and (at the other end - i.e. receiving) interpreted by the lawyers, with possibly equal effects (mostly financial and as overall impact on the business) as the tools we (the technical people) would be using to measure latency, uptime, bandwidth, jitter, etc... Stefan -- Muhammad Saqib Ilyas PhD Student, Computer Science and Engineering Lahore University of Management Sciences
Re: Network diagram software
On 11.02.2009, at 14:12, Malte von dem Hagen wrote: Mathias Wolkert wrote: I'd like to know what software people are using to document networks. Visio is obvious but feels like a straight jacket to me. I liked netviz but it seems owned by CA and unsupported nowadays. What do you use? OmniGraffle is the better Visio. Agree fully, I use OmniGraffle extensively and have for a long time. It's worth mentioning that OG can export to Visio-XML format, so you don't lock yourself into the .graffle format forever. Chris
