RE: which layer do the ospf bgp rip work on [7:20953]
hey, Cil, I'm wondering about the TTL's. I was doing some tech review for someone, and in the course of that reviewed some sniffer traces. OSPF was showing TTL's of 255. the traces were presented to me because I had asked about virtual link TTL's, which speculatively speaking would have to be very large, because the router could never know how many links a VL packet would have to traverse before it found the router noted as the other side, In any case, all OSPF traces, virtual link or otherwise, were showing a TTL of 255. maybe that's just Cisco? Do you have any speculation as to why the TTL would be 2 for the protocols you mention? Also, the BGP TTL can be manipulated through the use of the neighbor ebgp-multihop command Chuck -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Priscilla Oppenheimer Sent: Tuesday, September 25, 2001 5:20 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Couple additions (corrections). I just discovered that RIP, IGRP and EIGRP actually use a TTL of 2! (I had said that all routing protocol packets use a TTL of 1. OSPF and BGP do.) I stick to my main point that routing protocol packets go to directly-connected routers and could use just a data-link layer like IS-IS does. (Some routing protocols propagate messages to neighbors on the other side, but they don't simply forward packets at the IP layer). Also, I want to say that I should have been more precise, as Howard was: Routing protocols are layer management protocols at the network layer. Also, I liked this that he said: Just because a protocol is transmitted using a protocol at layer (N) doesn't make the payload protocol layer (N+1). If we think about it, there are other examples of this being true besides management protocols. It's pretty common to see the session-layer NetBIOS protocol running on top of LLC, for example. (It's sometimes called NetBEUI in this case, but it still has session-layer behavior.) Priscilla At 12:56 PM 9/25/01, Priscilla Oppenheimer wrote: At 07:05 AM 9/25/01, you wrote: hmm.. that's tricky, as I remember BGP used TCP for the routing update. RIP runs on top of UDP, so you would have to make the same argument for RIP, but it's not a good argument. Characterizing what layer they are at by what layer they reside on doesn't work. We could claim that all the routing protocols except IS-IS (which runs directly on top of LLC) are upper-layer protocols since they run on top of IP, but that doesn't work either. Theoretically they don't have to run on top of IP. They don't use IP's method for forwarding traffic across an internetwork. Every routing protocol packet I have ever seen has a TTL of 1. EIGRP can propagate queries, but that's not forwarding based on network-layer addresses. OSPF propagates Link State Updates, but that's not forwarding based on network-layer addresses either. Routing protocol packets are send to other routers on the same segment as either unicasts, broadcasts, or multicasts. Obviously, I have heard the argument before about routing protocols running at the application layer and there's some logic to it, as there is logic to characterizing the layer by what layers are below it, but it's just not based on reality regarding the definitions by ISO for their OSI reference model. The function of the network layer is forwarding packets across an internetwork and learning how to reach networks in the internetwork (routing protocols). The function of the application layer is providing services to end-user applications, such as e-mail, Telnet, Web browsing. By the way, with 7-layer bean dip, if you put the beans on top and the lettuce on the bottom, do the beans become lettuce and vice versa? ;-) Priscilla The only thing I can think of functionaly perhaps it's on layer 3, but interm of BGP itself, perhaps it's an application residing most certainly not in network layer. donny From: Priscilla Oppenheimer Reply-To: Priscilla Oppenheimer To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Date: Mon, 24 Sep 2001 23:27:16 -0400 Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com _ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp Priscilla Oppenheimer http://www.priscilla.com Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21266t=20953 -- FAQ, list archives, and subscription info: http
Re: which layer do the ospf bgp rip work on [7:20953]
Ya that may be been since when has ANSI been the authoritative source for correct spelling, I trust Merriam-Webster more... http://www.m-w.com/cgi-bin/dictionary fibre is a variant of fiber Dave Dr Rita Puzmanova wrote: Keeping myself - hopefully - unbiased in this spelling discussion (not being native English speaker) I would like to point out - FYI - that FIBRE CHANNEL is the ANSI standard?! Rita MADMAN wrote: Ah yes I should have known it was a British spelling, like centre, fibre, behaviour etc... When they gonna learn some good English ;) David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21141t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
You may trust Merriam-Webster, but if you want to find things in standards documents, I suggest you follow their rules. Ya that may be been since when has ANSI been the authoritative source for correct spelling, I trust Merriam-Webster more... http://www.m-w.com/cgi-bin/dictionary fibre is a variant of fiber Dave Dr Rita Puzmanova wrote: Keeping myself - hopefully - unbiased in this spelling discussion (not being native English speaker) I would like to point out - FYI - that FIBRE CHANNEL is the ANSI standard?! Rita MADMAN wrote: Ah yes I should have known it was a British spelling, like centre, fibre, behaviour etc... When they gonna learn some good English ;) David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21156t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
HorrayTally-ho.Chin-chin and all that ..us brits are first at something Marvelous... From: MADMAN Reply-To: MADMAN To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Date: Wed, 26 Sep 2001 10:17:16 -0400 Ya that may be been since when has ANSI been the authoritative source for correct spelling, I trust Merriam-Webster more... http://www.m-w.com/cgi-bin/dictionary fibre is a variant of fiber Dave Dr Rita Puzmanova wrote: Keeping myself - hopefully - unbiased in this spelling discussion (not being native English speaker) I would like to point out - FYI - that FIBRE CHANNEL is the ANSI standard?! Rita MADMAN wrote: Ah yes I should have known it was a British spelling, like centre, fibre, behaviour etc... When they gonna learn some good English ;) David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it _ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21169t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Yes of coarse but I was refering to spelling of fiber/fibre etc. not the standards describing there use and it was light hearted, I'm not going to worry about it much... Dave Howard C. Berkowitz wrote: You may trust Merriam-Webster, but if you want to find things in standards documents, I suggest you follow their rules. Ya that may be been since when has ANSI been the authoritative source for correct spelling, I trust Merriam-Webster more... http://www.m-w.com/cgi-bin/dictionary fibre is a variant of fiber Dave Dr Rita Puzmanova wrote: Keeping myself - hopefully - unbiased in this spelling discussion (not being native English speaker) I would like to point out - FYI - that FIBRE CHANNEL is the ANSI standard?! Rita MADMAN wrote: Ah yes I should have known it was a British spelling, like centre, fibre, behaviour etc... When they gonna learn some good English ;) David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21174t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: which layer do the ospf bgp rip work on [7:20953]
Priscilla; Couldn't it be argued that the *act* of routing is actually a layer 3 activity, however the routing protocols actually reside at the application layer. My reasoning for this, is if you look at the various routing protocols, their function is to exchange information, and it is a different process that actually forwards the packets. For example, you can configure a cisco router with static routes to build its routing table *or* you can configure OSPF, RIP, EIGRP, etc. Which results in new process running on the router to manage the information exchange, yet the actual routing of the packets are still managed by the same process that static routes uses. I am not necessarily disagreeing with you, just trying to start some conversation on the subject. Thanks __ Thomas Crowe Senior Systems Engineer / Architect CTS Professional Services - Atlanta Phone: 770-664-3900 *** Note New Cell Number *** Cell: 678-521-0360 __ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, September 24, 2001 11:27 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com [GroupStudy.com removed an attachment of type text/x-vcard which had a name of Thomas Crowe.vcf] Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20990t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: which layer do the ospf bgp rip work on [7:20953]
I dont agree cos BGP uses TCP for sending route updates and TCP is at transport layer. That has nothing to do with the placement of the protocol in the stack. It's a question of the payload, which is network layer information. Just because a protocol is transmitted using a protocol at layer (N) doesn't make the payload protocol layer (N+1). Management and control protocols do not have the same rules as application protocols. -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]] Sent: Monday, 24 September 2001 7:27 p.m. To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20994t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? They are layer management protocols at the network layer. This is not covered in the basic OSI Reference Model, but in the Management Annex to it, and the OSI Routeing Architecture document, both from ISO. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20992t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: which layer do the ospf bgp rip work on [7:20953]
Priscilla; Couldn't it be argued that the *act* of routing is actually a layer 3 activity, however the routing protocols actually reside at the application layer. My reasoning for this, is if you look at the various routing protocols, their function is to exchange information, and it is a different process that actually forwards the packets. For example, you can configure a cisco router with static routes to build its routing table *or* you can configure OSPF, RIP, EIGRP, etc. Which results in new process running on the router to manage the information exchange, yet the actual routing of the packets are still managed by the same process that static routes uses. I am not necessarily disagreeing with you, just trying to start some conversation on the subject. Thanks From the perspective of someone that actively worked on the ISO routeing architecture (and yes, that's the correct spelling), I'm not sure what purpose conversation serves. The management annex to the ISO reference model (I think it's ISO 7498-4) defines system management protocols (e.g., SNMP and CMIP agents) that live at the application layer, and layer management protocols that control other protocols at the same layer. Routing protocols are specifically defined as layer management. Static routes do start at the application layer, but are sent by system management to network layer management. Again people -- PLEASE do not assume the simple 7 layer model that Cisco tends to present was the end of all protocol stack development. It wasn't. If you want to coerce some protocol into a model (or a generation of the model) that doesn't include it, feel free. But what the actual source standards say isn't really a matter for discussion, unless you want to create new models. __ Thomas Crowe Senior Systems Engineer / Architect CTS Professional Services - Atlanta Phone: 770-664-3900 *** Note New Cell Number *** Cell: 678-521-0360 __ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, September 24, 2001 11:27 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com [GroupStudy.com removed an attachment of type text/x-vcard which had a name of Thomas Crowe.vcf] Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21009t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
At 07:05 AM 9/25/01, you wrote: hmm.. that's tricky, as I remember BGP used TCP for the routing update. RIP runs on top of UDP, so you would have to make the same argument for RIP, but it's not a good argument. Characterizing what layer they are at by what layer they reside on doesn't work. We could claim that all the routing protocols except IS-IS (which runs directly on top of LLC) are upper-layer protocols since they run on top of IP, but that doesn't work either. Theoretically they don't have to run on top of IP. They don't use IP's method for forwarding traffic across an internetwork. Every routing protocol packet I have ever seen has a TTL of 1. EIGRP can propagate queries, but that's not forwarding based on network-layer addresses. OSPF propagates Link State Updates, but that's not forwarding based on network-layer addresses either. Routing protocol packets are send to other routers on the same segment as either unicasts, broadcasts, or multicasts. Obviously, I have heard the argument before about routing protocols running at the application layer and there's some logic to it, as there is logic to characterizing the layer by what layers are below it, but it's just not based on reality regarding the definitions by ISO for their OSI reference model. The function of the network layer is forwarding packets across an internetwork and learning how to reach networks in the internetwork (routing protocols). The function of the application layer is providing services to end-user applications, such as e-mail, Telnet, Web browsing. By the way, with 7-layer bean dip, if you put the beans on top and the lettuce on the bottom, do the beans become lettuce and vice versa? ;-) Priscilla The only thing I can think of functionaly perhaps it's on layer 3, but interm of BGP itself, perhaps it's an application residing most certainly not in network layer. donny From: Priscilla Oppenheimer Reply-To: Priscilla Oppenheimer To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Date: Mon, 24 Sep 2001 23:27:16 -0400 Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com _ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21021t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Howard C. Berkowitz wrote: Geez, thanks, to think I have misspelled routing, err routeing for sooo long and had never been corrected :) Dave From the perspective of someone that actively worked on the ISO routeing architecture (and yes, that's the correct spelling), I'm not sure what purpose conversation serves. The management annex to the ISO reference model (I think it's ISO 7498-4) defines system management protocols (e.g., SNMP and CMIP agents) that live at the application layer, and layer management protocols that control other protocols at the same layer. Routing protocols are specifically defined as layer management. Static routes do start at the application layer, but are sent by system management to network layer management. Again people -- PLEASE do not assume the simple 7 layer model that Cisco tends to present was the end of all protocol stack development. It wasn't. If you want to coerce some protocol into a model (or a generation of the model) that doesn't include it, feel free. But what the actual source standards say isn't really a matter for discussion, unless you want to create new models. __ Thomas Crowe Senior Systems Engineer / Architect CTS Professional Services - Atlanta Phone: 770-664-3900 *** Note New Cell Number *** Cell: 678-521-0360 __ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, September 24, 2001 11:27 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com [GroupStudy.com removed an attachment of type text/x-vcard which had a name of Thomas Crowe.vcf] -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21024t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: which layer do the ospf bgp rip work on [7:20953]
Thank you for the clarification, Mr. Berkowitz.
Although I hope you won't be upset if I mention that you're not really
presenting a counter-point to the curriculum.
I continue to maintain that the CNAP curriculum (despite it's many problems)
is quite good when it comes to the model. It very clearly states that ospf,
bgp, rip, et. al. are all to be considered network layer protocols. It
doesn't make the distinction between layer management or not, but the
result is the same. As I've argued in previous discussions, a model is only
as good as the understanding that in facilitates.
I'm as quick to bash the currciculum as anyone (no VLSM until Sem 5?- Give
me a break!), but we should give credit where due, I think.
:-{)]
p.s. As always, Priscilla's answer was best. I've found that's a good rule
of thumb to follow...
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Re: which layer do the ospf bgp rip work on [7:20953]
Howard C. Berkowitz wrote: Geez, thanks, to think I have misspelled routing, err routeing for sooo long and had never been corrected :) It's ISO's idea of correct spelling. The British got there first. Dave From the perspective of someone that actively worked on the ISO routeing architecture (and yes, that's the correct spelling), I'm not sure what purpose conversation serves. The management annex to the ISO reference model (I think it's ISO 7498-4) defines system management protocols (e.g., SNMP and CMIP agents) that live at the application layer, and layer management protocols that control other protocols at the same layer. Routing protocols are specifically defined as layer management. Static routes do start at the application layer, but are sent by system management to network layer management. Again people -- PLEASE do not assume the simple 7 layer model that Cisco tends to present was the end of all protocol stack development. It wasn't. If you want to coerce some protocol into a model (or a generation of the model) that doesn't include it, feel free. But what the actual source standards say isn't really a matter for discussion, unless you want to create new models. __ Thomas Crowe Senior Systems Engineer / Architect CTS Professional Services - Atlanta Phone: 770-664-3900 *** Note New Cell Number *** Cell: 678-521-0360 __ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, September 24, 2001 11:27 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com [GroupStudy.com removed an attachment of type text/x-vcard which had a name of Thomas Crowe.vcf] -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21061t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: which layer do the ospf bgp rip work on [7:20953]
Thank you for the clarification, Mr. Berkowitz.
Although I hope you won't be upset if I mention that you're not really
presenting a counter-point to the curriculum.
A little confused...I didn't think I was responding to any specific
curriculum. I was responding to a point that someone made about
routing protocols being in the session or application layers.
I'm not even sure what CNAP is--Cisco Academy?
I continue to maintain that the CNAP curriculum (despite it's many problems)
is quite good when it comes to the model. It very clearly states that ospf,
bgp, rip, et. al. are all to be considered network layer protocols. It
doesn't make the distinction between layer management or not, but the
result is the same. As I've argued in previous discussions, a model is only
as good as the understanding that in facilitates.
I'm as quick to bash the currciculum as anyone (no VLSM until Sem 5?- Give
me a break!), but we should give credit where due, I think.
:-{)]
p.s. As always, Priscilla's answer was best. I've found that's a good rule
of thumb to follow...
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RE: which layer do the ospf bgp rip work on [7:20953]
Ah, I apologize. When you said:
Again people -- PLEASE do not assume the simple 7 layer model that
Cisco tends to present was the end of all protocol stack development.
It wasn't.
I thought you were referring to the CNAP (cisco networking academy program)
curriculum. If you ever get a chance to look at that, it does a pretty
decent job of keeping the model front and center and relevant.
Take Care!
:-{)]
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Re: which layer do the ospf bgp rip work on [7:20953]
Ah yes I should have known it was a British spelling, like centre, fibre, behaviour etc... When they gonna learn some good English ;) Dave Howard C. Berkowitz wrote: Howard C. Berkowitz wrote: Geez, thanks, to think I have misspelled routing, err routeing for sooo long and had never been corrected :) It's ISO's idea of correct spelling. The British got there first. Dave From the perspective of someone that actively worked on the ISO routeing architecture (and yes, that's the correct spelling), I'm not sure what purpose conversation serves. The management annex to the ISO reference model (I think it's ISO 7498-4) defines system management protocols (e.g., SNMP and CMIP agents) that live at the application layer, and layer management protocols that control other protocols at the same layer. Routing protocols are specifically defined as layer management. Static routes do start at the application layer, but are sent by system management to network layer management. Again people -- PLEASE do not assume the simple 7 layer model that Cisco tends to present was the end of all protocol stack development. It wasn't. If you want to coerce some protocol into a model (or a generation of the model) that doesn't include it, feel free. But what the actual source standards say isn't really a matter for discussion, unless you want to create new models. __ Thomas Crowe Senior Systems Engineer / Architect CTS Professional Services - Atlanta Phone: 770-664-3900 *** Note New Cell Number *** Cell: 678-521-0360 __ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, September 24, 2001 11:27 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com [GroupStudy.com removed an attachment of type text/x-vcard which had a name of Thomas Crowe.vcf] -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21074t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Keeping myself - hopefully - unbiased in this spelling discussion (not being native English speaker) I would like to point out - FYI - that FIBRE CHANNEL is the ANSI standard?! Rita MADMAN wrote: Ah yes I should have known it was a British spelling, like centre, fibre, behaviour etc... When they gonna learn some good English ;) Dave Howard C. Berkowitz wrote: Howard C. Berkowitz wrote: Geez, thanks, to think I have misspelled routing, err routeing for sooo long and had never been corrected :) It's ISO's idea of correct spelling. The British got there first. Dave From the perspective of someone that actively worked on the ISO routeing architecture (and yes, that's the correct spelling), I'm not sure what purpose conversation serves. The management annex to the ISO reference model (I think it's ISO 7498-4) defines system management protocols (e.g., SNMP and CMIP agents) that live at the application layer, and layer management protocols that control other protocols at the same layer. Routing protocols are specifically defined as layer management. Static routes do start at the application layer, but are sent by system management to network layer management. Again people -- PLEASE do not assume the simple 7 layer model that Cisco tends to present was the end of all protocol stack development. It wasn't. If you want to coerce some protocol into a model (or a generation of the model) that doesn't include it, feel free. But what the actual source standards say isn't really a matter for discussion, unless you want to create new models. __ Thomas Crowe Senior Systems Engineer / Architect CTS Professional Services - Atlanta Phone: 770-664-3900 *** Note New Cell Number *** Cell: 678-521-0360 __ -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] Sent: Monday, September 24, 2001 11:27 PM To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com [GroupStudy.com removed an attachment of type text/x-vcard which had a name of Thomas Crowe.vcf] -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it -- David Madland Sr. Network Engineer CCIE# 2016 Qwest Communications Int. Inc. [EMAIL PROTECTED] 612-664-3367 Emotion should reflect reason not guide it Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21080t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Couple additions (corrections). I just discovered that RIP, IGRP and EIGRP actually use a TTL of 2! (I had said that all routing protocol packets use a TTL of 1. OSPF and BGP do.) I stick to my main point that routing protocol packets go to directly-connected routers and could use just a data-link layer like IS-IS does. (Some routing protocols propagate messages to neighbors on the other side, but they don't simply forward packets at the IP layer). Also, I want to say that I should have been more precise, as Howard was: Routing protocols are layer management protocols at the network layer. Also, I liked this that he said: Just because a protocol is transmitted using a protocol at layer (N) doesn't make the payload protocol layer (N+1). If we think about it, there are other examples of this being true besides management protocols. It's pretty common to see the session-layer NetBIOS protocol running on top of LLC, for example. (It's sometimes called NetBEUI in this case, but it still has session-layer behavior.) Priscilla At 12:56 PM 9/25/01, Priscilla Oppenheimer wrote: At 07:05 AM 9/25/01, you wrote: hmm.. that's tricky, as I remember BGP used TCP for the routing update. RIP runs on top of UDP, so you would have to make the same argument for RIP, but it's not a good argument. Characterizing what layer they are at by what layer they reside on doesn't work. We could claim that all the routing protocols except IS-IS (which runs directly on top of LLC) are upper-layer protocols since they run on top of IP, but that doesn't work either. Theoretically they don't have to run on top of IP. They don't use IP's method for forwarding traffic across an internetwork. Every routing protocol packet I have ever seen has a TTL of 1. EIGRP can propagate queries, but that's not forwarding based on network-layer addresses. OSPF propagates Link State Updates, but that's not forwarding based on network-layer addresses either. Routing protocol packets are send to other routers on the same segment as either unicasts, broadcasts, or multicasts. Obviously, I have heard the argument before about routing protocols running at the application layer and there's some logic to it, as there is logic to characterizing the layer by what layers are below it, but it's just not based on reality regarding the definitions by ISO for their OSI reference model. The function of the network layer is forwarding packets across an internetwork and learning how to reach networks in the internetwork (routing protocols). The function of the application layer is providing services to end-user applications, such as e-mail, Telnet, Web browsing. By the way, with 7-layer bean dip, if you put the beans on top and the lettuce on the bottom, do the beans become lettuce and vice versa? ;-) Priscilla The only thing I can think of functionaly perhaps it's on layer 3, but interm of BGP itself, perhaps it's an application residing most certainly not in network layer. donny From: Priscilla Oppenheimer Reply-To: Priscilla Oppenheimer To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Date: Mon, 24 Sep 2001 23:27:16 -0400 Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com _ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp Priscilla Oppenheimer http://www.priscilla.com Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21081t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Couple additions (corrections). I just discovered that RIP, IGRP and EIGRP actually use a TTL of 2! (I had said that all routing protocol packets use a TTL of 1. OSPF and BGP do.) I stick to my main point that routing protocol packets go to directly-connected routers and could use just a data-link layer like IS-IS does. (Some routing protocols propagate messages to neighbors on the other side, but they don't simply forward packets at the IP layer). Also, I want to say that I should have been more precise, as Howard was: Routing protocols are layer management protocols at the network layer. Also, I liked this that he said: Just because a protocol is transmitted using a protocol at layer (N) doesn't make the payload protocol layer (N+1). You first pointed out to me how the official AppleTalk chart has this confused...ZIP and RTMP at the transport layer??? If we think about it, there are other examples of this being true besides management protocols. It's pretty common to see the session-layer NetBIOS protocol running on top of LLC, for example. (It's sometimes called NetBEUI in this case, but it still has session-layer behavior.) Other examples include the Enhanced Performance Architecture for robotic control, which runs the Manufacturing Message Service directly over LLC Type _3_. In other words, layers 3 through 6 are null. Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=21092t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
which layer do the ospf bgp rip work on [7:20953]
which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20953t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20958t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
RE: which layer do the ospf bgp rip work on [7:20953]
I dont agree cos BGP uses TCP for sending route updates and TCP is at transport layer. -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]] Sent: Monday, 24 September 2001 7:27 p.m. To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20960t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
Re: which layer do the ospf bgp rip work on [7:20953]
Raina, Priscilla is right. This would be one of those questions that are answered based on how the question is interpreted. Yes, you are right because BGP does use TCP(179), OSPF IP(89) and so on.. However, the question says which layer does ospf, bgp, and rip work on? The answer is layer 3, Network layer(routing). The protocol implementation in which they use TCP(179), IP(89), and UDP(520) would apply to the various mechanisms used to build, share, and gather the route/network information required to perform the one task they all have in common. Routing. HTH Nigel.. - Original Message - From: Tribavan Raina To: Sent: Tuesday, September 25, 2001 12:11 AM Subject: RE: which layer do the ospf bgp rip work on [7:20953] I dont agree cos BGP uses TCP for sending route updates and TCP is at transport layer. -Original Message- From: Priscilla Oppenheimer [mailto:[EMAIL PROTECTED]] Sent: Monday, 24 September 2001 7:27 p.m. To: [EMAIL PROTECTED] Subject: Re: which layer do the ospf bgp rip work on [7:20953] Network layer. Routing is a fundamental component of the network layer. At 10:14 PM 9/24/01, lhill peng wrote: which layer do the routing protocol such as ospf rip bgp eigrp work on? sb said that they are on application, others on network what is the right answer?? Priscilla Oppenheimer http://www.priscilla.com Message Posted at: http://www.groupstudy.com/form/read.php?f=7i=20963t=20953 -- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
