Re: (cisco, or any) acl *reducers* out there?
On 19 Aug 2010, at 04:23, George Michaelson wrote: something which can take a couple of hundred basic and extended ACLs and tell you these ten don't work these twenty conflict the remaining x have a sequence and can reduce to this basic x-y set A reasonable call. Its probably where we'll be by default, because there isn't anything there and I think first principles upward is better than paring back. [...] I think its clear a tool like I asked doesn't exist, and very probably won't, anytime soon. Hello [ I'm sorry this reply is so late, holiday season ] I understand the problem and think that it is partly caused by the complexity of keeping the acl configuration on all edge ports in sync, and keeping the acl definitions/purpose documented. The way around this, is to have a configuration management system that records the detail of the ACL (description / ticket number - along with the filter specification in generic terms), which generates the configuration - or even better uses flow-specification to distribute the rules. Further procedures to review the data in this management system periodically help this scale. For the config management, this would tend to have to be locally bespoke (but simple to produce) in order to fit with existing policy and procedure, but the glue to push these rules out to routers is easy as open source tools exist :- http://labs.ripe.net/Members/thomas_mangin/content-exabgp-new-tool-interact-bgp http://bgp.exa.org.uk/ Andy
Re: (cisco, or any) acl *reducers* out there?
Maybe FLINT? http://www.matasano.com/playbook/flint Never tried it so feedback is welcome... :-) /bs On Wed, Aug 18, 2010 at 5:38 PM, George Michaelson g...@apnic.net wrote: I have been looking at acl management s/w in the freecode space and I can find lots of tools which manage/distribute and test ACLs in routers. I'm wondering if anyone has written a parser which can construct rule-trees and get rid of the cruft, unusable, order-misorder and other issues in a large ACL pool? Its possible this is NP in the wider sense, but even a partial improvement would be useful something which can take a couple of hundred basic and extended ACLs and tell you these ten don't work these twenty conflict the remaining x have a sequence and can reduce to this basic x-y set (we've got the usual acquisition of rule by accretion problem across 4 edge/core routers with a mix of public facing, internal, WiFi, guest rules, and I hate to think this is either start from scratch, or intractable. The evidence is that its FRAGILE) -G
Re: (cisco, or any) acl *reducers* out there?
On Thu, 19 Aug 2010, George Michaelson wrote: I have been looking at acl management s/w in the freecode space and I can find lots of tools which manage/distribute and test ACLs in routers. I'm wondering if anyone has written a parser which can construct rule-trees and get rid of the cruft, unusable, order-misorder and other issues in a large ACL pool? Something similar to this? http://www.hpl.hp.com/techreports/2008/HPL-2008-111.pdf cheers! == A cat spends her life conflicted between a deep, passionate and profound desire for fish and an equally deep, passionate and profound desire to avoid getting wet. This is the defining metaphor of my life right now.
Re: (cisco, or any) acl *reducers* out there?
On Thu, Aug 19, 2010 at 11:55 AM, Cat Okita c...@reptiles.org wrote: On Thu, 19 Aug 2010, George Michaelson wrote: I have been looking at acl management s/w in the freecode space and I can find lots of tools which manage/distribute and test ACLs in routers. I'm wondering if anyone has written a parser which can construct rule-trees and get rid of the cruft, unusable, order-misorder and other issues in a large ACL pool? Something similar to this? http://www.hpl.hp.com/techreports/2008/HPL-2008-111.pdf this paper, while full of math and graphs and sh*t, doesn't make my acl management simpler, clearer or more complete... I keep trying to push my acls through the paper, no joy yet. there's code or something somewhere that implements the algorithms and graphs and sh*t that the paper shows in a pretty fashion? -Chris (btw, you owe me some neosporin to take care of all the paper cuts)
Re: (cisco, or any) acl *reducers* out there?
On Thu, 19 Aug 2010, Christopher Morrow wrote: this paper, while full of math and graphs and sh*t, doesn't make my acl management simpler, clearer or more complete... I keep trying to push my acls through the paper, no joy yet. there's code or something somewhere that implements the algorithms and graphs and sh*t that the paper shows in a pretty fashion? Heh. Of course there's code associated with it -- how else would we have managed to come up with numbers from practical application :P OTOH, without some idea of whether it's what he had in mind, it's pointless to push the battle to go anywhere with it. There are certainly some commercial products that do what he seemed to be asking about, as well -- but I'm failing to find references to them just now (nothing like illness and deadlines). (btw, you owe me some neosporin to take care of all the paper cuts) I've got some lovely iodine... :P cheers! == A cat spends her life conflicted between a deep, passionate and profound desire for fish and an equally deep, passionate and profound desire to avoid getting wet. This is the defining metaphor of my life right now.
Re: (cisco, or any) acl *reducers* out there?
On Thu, Aug 19, 2010 at 2:18 PM, Cat Okita c...@reptiles.org wrote: On Thu, 19 Aug 2010, Christopher Morrow wrote: this paper, while full of math and graphs and sh*t, doesn't make my acl management simpler, clearer or more complete... I keep trying to push my acls through the paper, no joy yet. there's code or something somewhere that implements the algorithms and graphs and sh*t that the paper shows in a pretty fashion? Heh. Of course there's code associated with it -- how else would we have managed to come up with numbers from practical application :P oh! I thought perhaps on them fancy HP 37 calculators? Seriously though, in a brief read I saw it talking about checkpoint firewall policy stuff... does the code include compiling to meta-state the policy? does it handle policy from things other than checkpoint? (like juniper router firewall syntax and pix and cisco acls?) OTOH, without some idea of whether it's what he had in mind, it's pointless to push the battle to go anywhere with it. There are certainly some commercial products that do what he seemed to be asking about, as well -- but I'm failing to find references to them just now (nothing like illness and deadlines). (btw, you owe me some neosporin to take care of all the paper cuts) I've got some lovely iodine... :P excellent! I love purple skin! -chris cheers! == A cat spends her life conflicted between a deep, passionate and profound desire for fish and an equally deep, passionate and profound desire to avoid getting wet. This is the defining metaphor of my life right now.
Re: (cisco, or any) acl *reducers* out there?
I'm wondering if anyone has written a parser which can construct rule-trees and get rid of the cruft, unusable, order-misorder and other issues in a large ACL pool? fwbuilder (www.fwbuilder.org) can import Cisco ACLs and impart a checkpoint-esque rule tree for you to look at, change, and test .. then recompile back into ACL syntax. Also works on IPtables, PF, and a few other things. Cheers, Michael Holstein Cleveland State University
(cisco, or any) acl *reducers* out there?
I have been looking at acl management s/w in the freecode space and I can find lots of tools which manage/distribute and test ACLs in routers. I'm wondering if anyone has written a parser which can construct rule-trees and get rid of the cruft, unusable, order-misorder and other issues in a large ACL pool? Its possible this is NP in the wider sense, but even a partial improvement would be useful something which can take a couple of hundred basic and extended ACLs and tell you these ten don't work these twenty conflict the remaining x have a sequence and can reduce to this basic x-y set (we've got the usual acquisition of rule by accretion problem across 4 edge/core routers with a mix of public facing, internal, WiFi, guest rules, and I hate to think this is either start from scratch, or intractable. The evidence is that its FRAGILE) -G
Re: (cisco, or any) acl *reducers* out there?
On Aug 19, 2010, at 7:38 AM, George Michaelson wrote: (we've got the usual acquisition of rule by accretion problem across 4 edge/core routers with a mix of public facing, internal, WiFi, guest rules, and I hate to think this is either start from scratch, or intractable. The evidence is that its FRAGILE) Attempts by various commercial solutions aside, there isn't really a workable, usable, scalable and reliable automated way to do this, AFAIK; apart from the complexity of the task itself, platform-specific ACL handling complicates matters further. To begin getting a handle on your ACLs, implement some form of revision control (RCS, CVS, subversion, whatever), and then work to modularize the ACLs by function: https://files.me.com/roland.dobbins/prguob Then take a look at whether the ACLs in question all actually belong on the edge, or whether it makes sense to break them out and instantiate the relevant policies at various points within the topology. --- Roland Dobbins rdobb...@arbor.net // http://www.arbornetworks.com Injustice is relatively easy to bear; what stings is justice. -- H.L. Mencken
Re: (cisco, or any) acl *reducers* out there?
On Wed, Aug 18, 2010 at 8:47 PM, Dobbins, Roland rdobb...@arbor.net wrote: On Aug 19, 2010, at 7:38 AM, George Michaelson wrote: (we've got the usual acquisition of rule by accretion problem across 4 edge/core routers with a mix of public facing, internal, WiFi, guest rules, and I hate to think this is either start from scratch, or intractable. The evidence is that its FRAGILE) Attempts by various commercial solutions aside, there isn't really a workable, usable, scalable and reliable automated way to do this, AFAIK; apart from the complexity of the task itself, platform-specific ACL handling complicates matters further. To begin getting a handle on your ACLs, implement some form of revision control (RCS, CVS, subversion, whatever), and then work to modularize the ACLs by function: https://files.me.com/roland.dobbins/prguob Then take a look at whether the ACLs in question all actually belong on the edge, or whether it makes sense to break them out and instantiate the relevant policies at various points within the topology. a plug for some google-peeps: http://code.google.com/p/capirca/ potentially once you make the definitions/policy-files you can use the proto-language to sort through your mess in a saner fashion. a nice aside is you can also create (from the same policy file) cisco/juniper/iptables configurations. (tony/pete really did a nice job on this) -chris --- Roland Dobbins rdobb...@arbor.net // http://www.arbornetworks.com Injustice is relatively easy to bear; what stings is justice. -- H.L. Mencken
Re: (cisco, or any) acl *reducers* out there?
something which can take a couple of hundred basic and extended ACLs and tell you these ten don't work these twenty conflict the remaining x have a sequence and can reduce to this basic x-y set maybe you could go the other direction. as opposed to trying to digest and correct cruft, generate the acls from something reasonable so that they are canonic by construction. randy
Re: (cisco, or any) acl *reducers* out there?
On 19/08/2010, at 1:00 PM, Randy Bush wrote: something which can take a couple of hundred basic and extended ACLs and tell you these ten don't work these twenty conflict the remaining x have a sequence and can reduce to this basic x-y set maybe you could go the other direction. as opposed to trying to digest and correct cruft, generate the acls from something reasonable so that they are canonic by construction. randy A reasonable call. Its probably where we'll be by default, because there isn't anything there and I think first principles upward is better than paring back. Thanks for the responses (and Roland!) I think its clear a tool like I asked doesn't exist, and very probably won't, anytime soon. cheers -G
Re: (cisco, or any) acl *reducers* out there?
one more comment. be careful aggregating filters. the peer may actually announce all those damed frags, especially in massively de-aggregated places such as india, indonesia, ... randy
Re: (cisco, or any) acl *reducers* out there?
On 19/08/2010, at 1:38 PM, Randy Bush wrote: one more comment. be careful aggregating filters. the peer may actually announce all those damed frags, especially in massively de-aggregated places such as india, indonesia, ... randy I should have been clearer that I really only want to aggregate ACLs like a port-22 ssh filter which has an endless list of specific /32, or the 'we don't like inbound UDP' -where it logically made sense. So if you happen to have an overarching UDP 'established' class rule, then its order compared to other rules might or might not make them useless. Route filtering is best done by professionals. Always read the instructions on the packet. (Your oven may be in centigrade, not fahrenheit, and the cup size varies by economy.) -George
