Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Thanks Peter for the clarification. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 5:32 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, On 19/08/2020 11:48, Veerendranatha Reddy V wrote: > Hi Peter, > Thanks for the reply. > As per the discussion, my understanding is Range TLV defined mainly be used > for SRMS entries (to get entries from LDP , for LDP Interoperability). > The use case mentioned is different from SRMS (redistribution across IGP > protocols) , Range TLV is not applicable to use in that use case? no. At this point, Range TLV is defined only for SRMS mapping advertisement. thanks, Peter > > Thanks & Regards, > Veerendranath > > > -Original Message- > From: Peter Psenak > Sent: Wednesday, August 19, 2020 3:04 PM > To: Veerendranatha Reddy V ; > lsr@ietf.org > Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for > External/NSSA prefixes defined in RFC 8665 > > Veerendranatha, > > On 19/08/2020 11:19, Veerendranatha Reddy V wrote: >> Hi Peter, >> Thanks for the reply. >> For OSPFv2 Extended Prefix TLV (defined in RFC 7684) has route type and it >> supports NSSA External Prefixes to carry SID information. >> In the same way, if Range TLV has Route-Type , we can extend to support for >> NSSA ASBR to send Range TLVs for redistributed prefixes. > > no. NSSA route type is used for redistribution of prefixes to NSSA areas. > There is no such thing as redistribution of SRMS entries. So using NSSA type > with SRMS advertisement is not valid. > > Peter > > > > >> >> Thanks & Regards, >> Veerendranath >> >> -Original Message- >> From: Peter Psenak >> Sent: Wednesday, August 19, 2020 1:39 PM >> To: Veerendranatha Reddy V ; >> lsr@ietf.org >> Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for >> External/NSSA prefixes defined in RFC 8665 >> >> Veerendranath, >> >> On 19/08/2020 10:03, Veerendranatha Reddy V wrote: >>> Hi Peter, >>> It is not related to SRMS. >>> If there exist ISIS/OSPF or two instances of OSPF in same device, and all >>> are supporting ST, then I can redistribute SR Prefix information to OSPF >>> from other OSPF instance or from ISIS. >> >> yes, you can. >> >>> In this case, I may use range TLV to reduce the number of Prefix TLVs, by >>> using Range TLV, if prefixes and SID are able to convert to Range TLV. >> >> you would have to generate one somewhere (on ABR?), but it would not be of >> NSSA type. >> >> Peter >> >> >>> >>> Thanks & Regards, >>> Veerendranath >>> >>> >>> -Original Message- >>> From: Peter Psenak >>> Sent: Wednesday, August 19, 2020 1:23 PM >>> To: Veerendranatha Reddy V ; >>> lsr@ietf.org >>> Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage >>> for External/NSSA prefixes defined in RFC 8665 >>> >>> Hi Veerendranatha, >>> >>> On 19/08/2020 06:23, Veerendranatha Reddy V wrote: >>>> Hi Peter, >>>> While redistributing prefix Sid for the prefixes from other protocols (Ex: >>>> from ISIS or other OSPF instances), we can consider as range TLV for the >>>> prefixes which are advertised in the range TLV in that protocol. >>> >>> I don't follow. Are you talking about redistribution of SRMS advertisement >>> between protocols? Such thing has not been defined. >>> >>> thanks, >>> Peter >>> >>> >>>> If it is NSSA, then we need to advertise these redistributed prefixes as >>>> area scope, so Range TLV also need to be part of area scope Opaque LSA. >>>> >>>> Thanks & Regards, >>>> Veerendranath >>>> >>>> -Original Message- >>>> From: Peter Psenak >>>> Sent: Tuesday, August 18, 2020 11:06 PM >>>> To: Veerendranatha Reddy V ; >>>> lsr@ietf.org >>>> Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage >>>> for External/NSSA prefixes defined in RFC 8665 >>>> >>>> Veerendranath, >>>> >>>> On 18/08/2020 16:40, Veerendranatha Reddy V wrote: >>>>> Hi Authors, All, >>>>> >>>>> OSPF Extended Pr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Veerendranatha, On 19/08/2020 11:48, Veerendranatha Reddy V wrote: Hi Peter, Thanks for the reply. As per the discussion, my understanding is Range TLV defined mainly be used for SRMS entries (to get entries from LDP , for LDP Interoperability). The use case mentioned is different from SRMS (redistribution across IGP protocols) , Range TLV is not applicable to use in that use case? no. At this point, Range TLV is defined only for SRMS mapping advertisement. thanks, Peter Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 3:04 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranatha, On 19/08/2020 11:19, Veerendranatha Reddy V wrote: Hi Peter, Thanks for the reply. For OSPFv2 Extended Prefix TLV (defined in RFC 7684) has route type and it supports NSSA External Prefixes to carry SID information. In the same way, if Range TLV has Route-Type , we can extend to support for NSSA ASBR to send Range TLVs for redistributed prefixes. no. NSSA route type is used for redistribution of prefixes to NSSA areas. There is no such thing as redistribution of SRMS entries. So using NSSA type with SRMS advertisement is not valid. Peter Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:39 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 19/08/2020 10:03, Veerendranatha Reddy V wrote: Hi Peter, It is not related to SRMS. If there exist ISIS/OSPF or two instances of OSPF in same device, and all are supporting ST, then I can redistribute SR Prefix information to OSPF from other OSPF instance or from ISIS. yes, you can. In this case, I may use range TLV to reduce the number of Prefix TLVs, by using Range TLV, if prefixes and SID are able to convert to Range TLV. you would have to generate one somewhere (on ABR?), but it would not be of NSSA type. Peter Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:23 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, On 19/08/2020 06:23, Veerendranatha Reddy V wrote: Hi Peter, While redistributing prefix Sid for the prefixes from other protocols (Ex: from ISIS or other OSPF instances), we can consider as range TLV for the prefixes which are advertised in the range TLV in that protocol. I don't follow. Are you talking about redistribution of SRMS advertisement between protocols? Such thing has not been defined. thanks, Peter If it is NSSA, then we need to advertise these redistributed prefixes as area scope, so Range TLV also need to be part of area scope Opaque LSA. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Tuesday, August 18, 2020 11:06 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: Hi Authors, All, OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to distinguish between Intra and Inter Area scope prefixes. Whether any restrictions to not to use Prefix Range TLV for external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter For External Prefixes, we can able to use Prefix Range TLV by using LSA type (based on AS scope Opaque Type , so the TLV is for External Prefixes) But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) , which are in area scope, there is no flag/route-type field in this TLV to distinguish between Intra or NSSA prefixes( as IA flag will not be set anyway). Thanks & Regards, Veerendranath ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Peter, Thanks for the reply. For OSPFv2 Extended Prefix TLV (defined in RFC 7684) has route type and it supports NSSA External Prefixes to carry SID information. In the same way, if Range TLV has Route-Type , we can extend to support for NSSA ASBR to send Range TLVs for redistributed prefixes. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:39 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 19/08/2020 10:03, Veerendranatha Reddy V wrote: > Hi Peter, > It is not related to SRMS. > If there exist ISIS/OSPF or two instances of OSPF in same device, and all are > supporting ST, then I can redistribute SR Prefix information to OSPF from > other OSPF instance or from ISIS. yes, you can. > In this case, I may use range TLV to reduce the number of Prefix TLVs, by > using Range TLV, if prefixes and SID are able to convert to Range TLV. you would have to generate one somewhere (on ABR?), but it would not be of NSSA type. Peter > > Thanks & Regards, > Veerendranath > > > -Original Message- > From: Peter Psenak > Sent: Wednesday, August 19, 2020 1:23 PM > To: Veerendranatha Reddy V ; > lsr@ietf.org > Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for > External/NSSA prefixes defined in RFC 8665 > > Hi Veerendranatha, > > On 19/08/2020 06:23, Veerendranatha Reddy V wrote: >> Hi Peter, >> While redistributing prefix Sid for the prefixes from other protocols (Ex: >> from ISIS or other OSPF instances), we can consider as range TLV for the >> prefixes which are advertised in the range TLV in that protocol. > > I don't follow. Are you talking about redistribution of SRMS advertisement > between protocols? Such thing has not been defined. > > thanks, > Peter > > >> If it is NSSA, then we need to advertise these redistributed prefixes as >> area scope, so Range TLV also need to be part of area scope Opaque LSA. >> >> Thanks & Regards, >> Veerendranath >> >> -----Original Message----- >> From: Peter Psenak >> Sent: Tuesday, August 18, 2020 11:06 PM >> To: Veerendranatha Reddy V ; >> lsr@ietf.org >> Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for >> External/NSSA prefixes defined in RFC 8665 >> >> Veerendranath, >> >> On 18/08/2020 16:40, Veerendranatha Reddy V wrote: >>> Hi Authors, All, >>> >>> OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to >>> distinguish between Intra and Inter Area scope prefixes. >>> >>> Whether any restrictions to not to use Prefix Range TLV for >>> external/NSSA prefixes ? >> >> I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the >> usage of OSPF Extended Prefix Range TLV has only been defined in the context >> of RFC 8665. >> >> thanks, >> Peter >> >> >>> >>> For External Prefixes, we can able to use Prefix Range TLV by >>> using LSA type (based on AS scope Opaque Type , so the TLV is for >>> External >>> Prefixes) >>> >>> But If we need to use the Prefix Range TLV for NSSA prefixes >>> (Type-7) , which are in area scope, there is no flag/route-type >>> field in this TLV to distinguish between Intra or NSSA prefixes( as >>> IA flag will not be set anyway). >>> >>> Thanks & Regards, >>> >>> Veerendranath >>> >> >> >> > > > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Peter, Thanks for the reply. As per the discussion, my understanding is Range TLV defined mainly be used for SRMS entries (to get entries from LDP , for LDP Interoperability). The use case mentioned is different from SRMS (redistribution across IGP protocols) , Range TLV is not applicable to use in that use case? Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 3:04 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranatha, On 19/08/2020 11:19, Veerendranatha Reddy V wrote: > Hi Peter, > Thanks for the reply. > For OSPFv2 Extended Prefix TLV (defined in RFC 7684) has route type and it > supports NSSA External Prefixes to carry SID information. > In the same way, if Range TLV has Route-Type , we can extend to support for > NSSA ASBR to send Range TLVs for redistributed prefixes. no. NSSA route type is used for redistribution of prefixes to NSSA areas. There is no such thing as redistribution of SRMS entries. So using NSSA type with SRMS advertisement is not valid. Peter > > Thanks & Regards, > Veerendranath > > -Original Message- > From: Peter Psenak > Sent: Wednesday, August 19, 2020 1:39 PM > To: Veerendranatha Reddy V ; > lsr@ietf.org > Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for > External/NSSA prefixes defined in RFC 8665 > > Veerendranath, > > On 19/08/2020 10:03, Veerendranatha Reddy V wrote: >> Hi Peter, >> It is not related to SRMS. >> If there exist ISIS/OSPF or two instances of OSPF in same device, and all >> are supporting ST, then I can redistribute SR Prefix information to OSPF >> from other OSPF instance or from ISIS. > > yes, you can. > >> In this case, I may use range TLV to reduce the number of Prefix TLVs, by >> using Range TLV, if prefixes and SID are able to convert to Range TLV. > > you would have to generate one somewhere (on ABR?), but it would not be of > NSSA type. > > Peter > > >> >> Thanks & Regards, >> Veerendranath >> >> >> -Original Message- >> From: Peter Psenak >> Sent: Wednesday, August 19, 2020 1:23 PM >> To: Veerendranatha Reddy V ; >> lsr@ietf.org >> Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for >> External/NSSA prefixes defined in RFC 8665 >> >> Hi Veerendranatha, >> >> On 19/08/2020 06:23, Veerendranatha Reddy V wrote: >>> Hi Peter, >>> While redistributing prefix Sid for the prefixes from other protocols (Ex: >>> from ISIS or other OSPF instances), we can consider as range TLV for the >>> prefixes which are advertised in the range TLV in that protocol. >> >> I don't follow. Are you talking about redistribution of SRMS advertisement >> between protocols? Such thing has not been defined. >> >> thanks, >> Peter >> >> >>> If it is NSSA, then we need to advertise these redistributed prefixes as >>> area scope, so Range TLV also need to be part of area scope Opaque LSA. >>> >>> Thanks & Regards, >>> Veerendranath >>> >>> -Original Message- >>> From: Peter Psenak >>> Sent: Tuesday, August 18, 2020 11:06 PM >>> To: Veerendranatha Reddy V ; >>> lsr@ietf.org >>> Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage >>> for External/NSSA prefixes defined in RFC 8665 >>> >>> Veerendranath, >>> >>> On 18/08/2020 16:40, Veerendranatha Reddy V wrote: >>>> Hi Authors, All, >>>> >>>> OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to >>>> distinguish between Intra and Inter Area scope prefixes. >>>> >>>> Whether any restrictions to not to use Prefix Range TLV for >>>> external/NSSA prefixes ? >>> >>> I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the >>> usage of OSPF Extended Prefix Range TLV has only been defined in the >>> context of RFC 8665. >>> >>> thanks, >>> Peter >>> >>> >>>> >>>> For External Prefixes, we can able to use Prefix Range TLV by >>>> using LSA type (based on AS scope Opaque Type , so the TLV is for >>>> External >>>> Prefixes) >>>> >>>> But If we need to use the Prefix Range TLV for NSSA prefixes >>>> (Type-7) , which are in area scope, there is no flag/route-type >>>> field in this TLV to distinguish between Intra or NSSA prefixes( as >>>> IA flag will not be set anyway). >>>> >>>> Thanks & Regards, >>>> >>>> Veerendranath >>>> >>> >>> >>> >> >> >> > > > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Peter, It is not related to SRMS. If there exist ISIS/OSPF or two instances of OSPF in same device, and all are supporting ST, then I can redistribute SR Prefix information to OSPF from other OSPF instance or from ISIS. In this case, I may use range TLV to reduce the number of Prefix TLVs, by using Range TLV, if prefixes and SID are able to convert to Range TLV. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:23 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, On 19/08/2020 06:23, Veerendranatha Reddy V wrote: > Hi Peter, > While redistributing prefix Sid for the prefixes from other protocols (Ex: > from ISIS or other OSPF instances), we can consider as range TLV for the > prefixes which are advertised in the range TLV in that protocol. I don't follow. Are you talking about redistribution of SRMS advertisement between protocols? Such thing has not been defined. thanks, Peter > If it is NSSA, then we need to advertise these redistributed prefixes as area > scope, so Range TLV also need to be part of area scope Opaque LSA. > > Thanks & Regards, > Veerendranath > > -Original Message- > From: Peter Psenak > Sent: Tuesday, August 18, 2020 11:06 PM > To: Veerendranatha Reddy V ; > lsr@ietf.org > Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for > External/NSSA prefixes defined in RFC 8665 > > Veerendranath, > > On 18/08/2020 16:40, Veerendranatha Reddy V wrote: >> Hi Authors, All, >> >> OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to >> distinguish between Intra and Inter Area scope prefixes. >> >> Whether any restrictions to not to use Prefix Range TLV for >> external/NSSA prefixes ? > > I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the > usage of OSPF Extended Prefix Range TLV has only been defined in the context > of RFC 8665. > > thanks, > Peter > > >> >> For External Prefixes, we can able to use Prefix Range TLV by using >> LSA type (based on AS scope Opaque Type , so the TLV is for External >> Prefixes) >> >> But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) >> , which are in area scope, there is no flag/route-type field in this >> TLV to distinguish between Intra or NSSA prefixes( as IA flag will >> not be set anyway). >> >> Thanks & Regards, >> >> Veerendranath >> > > > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Ketan, Please find the response in line. The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. [V] As per RFC, IA-Flag: Inter-Area Flag. If set, advertisement is of inter-area type. An Area Border Router (ABR) that is advertising the OSPF Extended Prefix Range TLV between areas MUST set this bit. I thought, when prefix Ranges with SID are advertised from Intra to Inter, we need to set this flag. So that it indicates the prefixes are of inter area type. Please let me know if my understanding is not correct. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). [V] If ASBR is part of NSSA, and if we redistributed Prefix SIDs learnt form other protocols or other instance of OSPF, and those prefixes are result of Range TLV in that protocol, we can apply range in dest ospf instance Thanks & Regards, Veerendranath -Original Message- From: Ketan Talaulikar (ketant) Sent: Tuesday, August 18, 2020 11:28 PM To: Peter Psenak ; Veerendranatha Reddy V ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). I am not sure if that answers your question. Thanks, Ketan -Original Message- From: Lsr On Behalf Of Peter Psenak Sent: 18 August 2020 23:06 To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: > Hi Authors, All, > > OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to > distinguish between Intra and Inter Area scope prefixes. > > Whether any restrictions to not to use Prefix Range TLV for > external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter > > For External Prefixes, we can able to use Prefix Range TLV by using > LSA type (based on AS scope Opaque Type , so the TLV is for External > Prefixes) > > But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) > , which are in area scope, there is no flag/route-type field in this > TLV to distinguish between Intra or NSSA prefixes( as IA flag will not > be set anyway). > > Thanks & Regards, > > Veerendranath > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Ketan, Please find the response in line. The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. [V] As per RFC, IA-Flag: Inter-Area Flag. If set, advertisement is of inter-area type. An Area Border Router (ABR) that is advertising the OSPF Extended Prefix Range TLV between areas MUST set this bit. I thought, when prefix Ranges with SID are advertised from Intra to Inter, we need to set this flag. So that it indicates the prefixes are of inter area type. Please let me know if my understanding is not correct. [KT] What is says is "the prefix range advertisement is of type inter-area or intra-area" (think of it as somewhat equivalent of the D bit in ISIS when leaking across levels). That does not mean that the advertised mappings need to be used for only for intra or inter area prefixes respectively. [V] When we receive the range TLV received at ABR, while it is originating opaque LSA for that range TLV across the other areas, whether it is required to set IA or not? When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). [V] If ASBR is part of NSSA, and if we redistributed Prefix SIDs learnt form other protocols or other instance of OSPF, and those prefixes are result of Range TLV in that protocol, we can apply range in dest ospf instance [KT] I do not follow above statement - can you please try to elaborate/re-phrase? [V] When redistributing Prefix SID information to NSSA from other protocols , it may possible to generate Range TLV, if multiple prefixes can be aggregated as range., instead of generating extended Prefix TLV for each prefix. So while originating this range TLV, how we can differentiate whether it is intra Scope or NSSA scope. So that when it is received at ABR, he will consider to translate to inter area Opaque or External Opaque for that range. Thanks & Regards, Veerendranath -Original Message- From: Ketan Talaulikar (ketant) Sent: Wednesday, August 19, 2020 10:27 AM To: Veerendranatha Reddy V ; Peter Psenak (ppsenak) ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, Please check inline below. -Original Message- From: Veerendranatha Reddy V Sent: 19 August 2020 10:03 To: Ketan Talaulikar (ketant) ; Peter Psenak (ppsenak) ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Ketan, Please find the response in line. The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. [V] As per RFC, IA-Flag: Inter-Area Flag. If set, advertisement is of inter-area type. An Area Border Router (ABR) that is advertising the OSPF Extended Prefix Range TLV between areas MUST set this bit. I thought, when prefix Ranges with SID are advertised from Intra to Inter, we need to set this flag. So that it indicates the prefixes are of inter area type. Please let me know if my understanding is not correct. [KT] What is says is "the prefix range advertisement is of type inter-area or intra-area" (think of it as somewhat equivalent of the D bit in ISIS when leaking across levels). That does not mean that the advertised mappings need to be used for only for intra or inter area prefixes respectively. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). [V] If ASBR is part of NSSA, and if we redistributed Prefix SIDs learnt form other protocols or other instance of OSPF, and those prefixes are result of Range TLV in that protocol, we can apply range in dest ospf instance [KT] I do not follow above statement - can you please try to elaborate/re-phrase? Thanks, Ketan Thanks & Regards, Veerendranath -Original Message- From: Ketan Talaulikar (ketant) Sent: Tuesday, August 18, 2020 11:28 PM To: Peter Psenak ; Veerendranatha Reddy V ; ls
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Peter, While redistributing prefix Sid for the prefixes from other protocols (Ex: from ISIS or other OSPF instances), we can consider as range TLV for the prefixes which are advertised in the range TLV in that protocol. If it is NSSA, then we need to advertise these redistributed prefixes as area scope, so Range TLV also need to be part of area scope Opaque LSA. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Tuesday, August 18, 2020 11:06 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: > Hi Authors, All, > > OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to > distinguish between Intra and Inter Area scope prefixes. > > Whether any restrictions to not to use Prefix Range TLV for > external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter > > For External Prefixes, we can able to use Prefix Range TLV by using > LSA type (based on AS scope Opaque Type , so the TLV is for External > Prefixes) > > But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) > , which are in area scope, there is no flag/route-type field in this > TLV to distinguish between Intra or NSSA prefixes( as IA flag will not > be set anyway). > > Thanks & Regards, > > Veerendranath > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Veerendranatha, Please check inline below with [KT2] -Original Message- From: Veerendranatha Reddy V Sent: 19 August 2020 13:07 To: Ketan Talaulikar (ketant) ; Peter Psenak (ppsenak) ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Ketan, Please find the response in line. The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. [V] As per RFC, IA-Flag: Inter-Area Flag. If set, advertisement is of inter-area type. An Area Border Router (ABR) that is advertising the OSPF Extended Prefix Range TLV between areas MUST set this bit. I thought, when prefix Ranges with SID are advertised from Intra to Inter, we need to set this flag. So that it indicates the prefixes are of inter area type. Please let me know if my understanding is not correct. [KT] What is says is "the prefix range advertisement is of type inter-area or intra-area" (think of it as somewhat equivalent of the D bit in ISIS when leaking across levels). That does not mean that the advertised mappings need to be used for only for intra or inter area prefixes respectively. [V] When we receive the range TLV received at ABR, while it is originating opaque LSA for that range TLV across the other areas, whether it is required to set IA or not? [KT2] Yes - please check the RFC8665 Sec 4 - right after where the IA flag is described. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). [V] If ASBR is part of NSSA, and if we redistributed Prefix SIDs learnt form other protocols or other instance of OSPF, and those prefixes are result of Range TLV in that protocol, we can apply range in dest ospf instance [KT] I do not follow above statement - can you please try to elaborate/re-phrase? [V] When redistributing Prefix SID information to NSSA from other protocols , it may possible to generate Range TLV, if multiple prefixes can be aggregated as range., instead of generating extended Prefix TLV for each prefix. So while originating this range TLV, how we can differentiate whether it is intra Scope or NSSA scope. So that when it is received at ABR, he will consider to translate to inter area Opaque or External Opaque for that range. [KT2] I believe Peter answered and clarified this part. There is no notion of NSSA area or NSSA-scope flooding for the Extended Prefix Range TLV. Thanks, Ketan Thanks & Regards, Veerendranath -Original Message- From: Ketan Talaulikar (ketant) Sent: Wednesday, August 19, 2020 10:27 AM To: Veerendranatha Reddy V ; Peter Psenak (ppsenak) ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, Please check inline below. -Original Message- From: Veerendranatha Reddy V Sent: 19 August 2020 10:03 To: Ketan Talaulikar (ketant) ; Peter Psenak (ppsenak) ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Ketan, Please find the response in line. The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. [V] As per RFC, IA-Flag: Inter-Area Flag. If set, advertisement is of inter-area type. An Area Border Router (ABR) that is advertising the OSPF Extended Prefix Range TLV between areas MUST set this bit. I thought, when prefix Ranges with SID are advertised from Intra to Inter, we need to set this flag. So that it indicates the prefixes are of inter area type. Please let me know if my understanding is not correct. [KT] What is says is "the prefix range advertisement is of type inter-area or intra-area" (think of it as somewhat equivalent of the D bit in ISIS when leaking across levels). That does not mean that the advertised mappings need to be used for only for intra or inter area prefixes respectively. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Veerendranatha, On 19/08/2020 11:19, Veerendranatha Reddy V wrote: Hi Peter, Thanks for the reply. For OSPFv2 Extended Prefix TLV (defined in RFC 7684) has route type and it supports NSSA External Prefixes to carry SID information. In the same way, if Range TLV has Route-Type , we can extend to support for NSSA ASBR to send Range TLVs for redistributed prefixes. no. NSSA route type is used for redistribution of prefixes to NSSA areas. There is no such thing as redistribution of SRMS entries. So using NSSA type with SRMS advertisement is not valid. Peter Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:39 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 19/08/2020 10:03, Veerendranatha Reddy V wrote: Hi Peter, It is not related to SRMS. If there exist ISIS/OSPF or two instances of OSPF in same device, and all are supporting ST, then I can redistribute SR Prefix information to OSPF from other OSPF instance or from ISIS. yes, you can. In this case, I may use range TLV to reduce the number of Prefix TLVs, by using Range TLV, if prefixes and SID are able to convert to Range TLV. you would have to generate one somewhere (on ABR?), but it would not be of NSSA type. Peter Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:23 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, On 19/08/2020 06:23, Veerendranatha Reddy V wrote: Hi Peter, While redistributing prefix Sid for the prefixes from other protocols (Ex: from ISIS or other OSPF instances), we can consider as range TLV for the prefixes which are advertised in the range TLV in that protocol. I don't follow. Are you talking about redistribution of SRMS advertisement between protocols? Such thing has not been defined. thanks, Peter If it is NSSA, then we need to advertise these redistributed prefixes as area scope, so Range TLV also need to be part of area scope Opaque LSA. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Tuesday, August 18, 2020 11:06 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: Hi Authors, All, OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to distinguish between Intra and Inter Area scope prefixes. Whether any restrictions to not to use Prefix Range TLV for external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter For External Prefixes, we can able to use Prefix Range TLV by using LSA type (based on AS scope Opaque Type , so the TLV is for External Prefixes) But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) , which are in area scope, there is no flag/route-type field in this TLV to distinguish between Intra or NSSA prefixes( as IA flag will not be set anyway). Thanks & Regards, Veerendranath ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Veerendranath, On 19/08/2020 10:03, Veerendranatha Reddy V wrote: Hi Peter, It is not related to SRMS. If there exist ISIS/OSPF or two instances of OSPF in same device, and all are supporting ST, then I can redistribute SR Prefix information to OSPF from other OSPF instance or from ISIS. yes, you can. In this case, I may use range TLV to reduce the number of Prefix TLVs, by using Range TLV, if prefixes and SID are able to convert to Range TLV. you would have to generate one somewhere (on ABR?), but it would not be of NSSA type. Peter Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Wednesday, August 19, 2020 1:23 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Veerendranatha, On 19/08/2020 06:23, Veerendranatha Reddy V wrote: Hi Peter, While redistributing prefix Sid for the prefixes from other protocols (Ex: from ISIS or other OSPF instances), we can consider as range TLV for the prefixes which are advertised in the range TLV in that protocol. I don't follow. Are you talking about redistribution of SRMS advertisement between protocols? Such thing has not been defined. thanks, Peter If it is NSSA, then we need to advertise these redistributed prefixes as area scope, so Range TLV also need to be part of area scope Opaque LSA. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Tuesday, August 18, 2020 11:06 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: Hi Authors, All, OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to distinguish between Intra and Inter Area scope prefixes. Whether any restrictions to not to use Prefix Range TLV for external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter For External Prefixes, we can able to use Prefix Range TLV by using LSA type (based on AS scope Opaque Type , so the TLV is for External Prefixes) But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) , which are in area scope, there is no flag/route-type field in this TLV to distinguish between Intra or NSSA prefixes( as IA flag will not be set anyway). Thanks & Regards, Veerendranath ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Veerendranatha, On 19/08/2020 06:23, Veerendranatha Reddy V wrote: Hi Peter, While redistributing prefix Sid for the prefixes from other protocols (Ex: from ISIS or other OSPF instances), we can consider as range TLV for the prefixes which are advertised in the range TLV in that protocol. I don't follow. Are you talking about redistribution of SRMS advertisement between protocols? Such thing has not been defined. thanks, Peter If it is NSSA, then we need to advertise these redistributed prefixes as area scope, so Range TLV also need to be part of area scope Opaque LSA. Thanks & Regards, Veerendranath -Original Message- From: Peter Psenak Sent: Tuesday, August 18, 2020 11:06 PM To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: Hi Authors, All, OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to distinguish between Intra and Inter Area scope prefixes. Whether any restrictions to not to use Prefix Range TLV for external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter For External Prefixes, we can able to use Prefix Range TLV by using LSA type (based on AS scope Opaque Type , so the TLV is for External Prefixes) But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) , which are in area scope, there is no flag/route-type field in this TLV to distinguish between Intra or NSSA prefixes( as IA flag will not be set anyway). Thanks & Regards, Veerendranath ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Hi Veerendranatha, Please check inline below. -Original Message- From: Veerendranatha Reddy V Sent: 19 August 2020 10:03 To: Ketan Talaulikar (ketant) ; Peter Psenak (ppsenak) ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Hi Ketan, Please find the response in line. The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. [V] As per RFC, IA-Flag: Inter-Area Flag. If set, advertisement is of inter-area type. An Area Border Router (ABR) that is advertising the OSPF Extended Prefix Range TLV between areas MUST set this bit. I thought, when prefix Ranges with SID are advertised from Intra to Inter, we need to set this flag. So that it indicates the prefixes are of inter area type. Please let me know if my understanding is not correct. [KT] What is says is "the prefix range advertisement is of type inter-area or intra-area" (think of it as somewhat equivalent of the D bit in ISIS when leaking across levels). That does not mean that the advertised mappings need to be used for only for intra or inter area prefixes respectively. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). [V] If ASBR is part of NSSA, and if we redistributed Prefix SIDs learnt form other protocols or other instance of OSPF, and those prefixes are result of Range TLV in that protocol, we can apply range in dest ospf instance [KT] I do not follow above statement - can you please try to elaborate/re-phrase? Thanks, Ketan Thanks & Regards, Veerendranath -Original Message- From: Ketan Talaulikar (ketant) Sent: Tuesday, August 18, 2020 11:28 PM To: Peter Psenak ; Veerendranatha Reddy V ; lsr@ietf.org Subject: RE: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). I am not sure if that answers your question. Thanks, Ketan -Original Message- From: Lsr On Behalf Of Peter Psenak Sent: 18 August 2020 23:06 To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: > Hi Authors, All, > > OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to > distinguish between Intra and Inter Area scope prefixes. > > Whether any restrictions to not to use Prefix Range TLV for > external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter > > For External Prefixes, we can able to use Prefix Range TLV by using > LSA type (based on AS scope Opaque Type , so the TLV is for External > Prefixes) > > But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) > , which are in area scope, there is no flag/route-type field in this > TLV to distinguish between Intra or NSSA prefixes( as IA flag will not > be set anyway). > > Thanks & Regards, > > Veerendranath > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
The IA flag in the OSPF Extended Prefix Range TLV does not indicate that the prefix-SID mapping advertised via it is for use for only intra or inter area prefixes. The mappings can be used for assignment of SIDs for ALL types of OSPF prefixes - regardless of the IA bit. The IA flag is only to prevent looping during flooding of area-scoped LSAs with OSPF Extended Prefix Range TLVs when they are propagated across areas. When OSPF Extended Prefix Range TLVs are advertised using AS-scope, the NSSA notion does not apply for them and does not restrict their flooding into or from NSSA areas (or stub areas for that matter). I am not sure if that answers your question. Thanks, Ketan -Original Message- From: Lsr On Behalf Of Peter Psenak Sent: 18 August 2020 23:06 To: Veerendranatha Reddy V ; lsr@ietf.org Subject: Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665 Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: > Hi Authors, All, > > OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to > distinguish between Intra and Inter Area scope prefixes. > > Whether any restrictions to not to use Prefix Range TLV for > external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter > > For External Prefixes, we can able to use Prefix Range TLV by using > LSA type (based on AS scope Opaque Type , so the TLV is for External > Prefixes) > > But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) > , which are in area scope, there is no flag/route-type field in this > TLV to distinguish between Intra or NSSA prefixes( as IA flag will not > be set anyway). > > Thanks & Regards, > > Veerendranath > ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
Re: [Lsr] Regarding OSPF Extended Prefix Range TLV usage for External/NSSA prefixes defined in RFC 8665
Veerendranath, On 18/08/2020 16:40, Veerendranatha Reddy V wrote: Hi Authors, All, OSPF Extended Prefix Range TLV defined in RFC 8665 has IA flag to distinguish between Intra and Inter Area scope prefixes. Whether any restrictions to not to use Prefix Range TLV for external/NSSA prefixes ? I don't see how you can use OSPF Extended Prefix Range TLV for NSSA, the usage of OSPF Extended Prefix Range TLV has only been defined in the context of RFC 8665. thanks, Peter For External Prefixes, we can able to use Prefix Range TLV by using LSA type (based on AS scope Opaque Type , so the TLV is for External Prefixes) But If we need to use the Prefix Range TLV for NSSA prefixes (Type-7) , which are in area scope, there is no flag/route-type field in this TLV to distinguish between Intra or NSSA prefixes( as IA flag will not be set anyway). Thanks & Regards, Veerendranath ___ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
