Re: Methods to label the passive interfaces within ISIS
[email protected] Thu, 9 Jan 2020 23:26:33 -0800
| Newsgroups | gmane.ietf.isis |
|---|---|
| Message-ID | <[email protected]> |
--===============5547584854968804324== Content-Type: multipart/alternative; boundary="Apple-Mail=_2464CEED-AD95-4366-8D0C-427F300E5086" --Apple-Mail=_2464CEED-AD95-4366-8D0C-427F300E5086 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Hi Aijun, > For the link attributes that defined in RFC5029, as that stated in = https://tools.ietf.org/html/rfc5029#section-2 = <https://tools.ietf.org/html/rfc5029#section-2>, this sub-TLV is = included in the TLV 22(Extended IS Reachability).=20 > As I read the IANA code point = https://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-codepoints.x= html#isis-tlv-codepoints-22-23-25-141-222-223 = <https://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-codepoints.= xhtml#isis-tlv-codepoints-22-23-25-141-222-223>, it notes this sub-TLV = can be included in all of these TLVs (22,23,25,141,222,223).=20 > =20 > But, when the interface is configured as passive/stub, it seems that = the above TLVs will not be advertised, because there is no IS neighbor = on this passive link. =20 Fair point. Given that there is an IP address and prefix on that link, = it would be very reasonable to advertise the Extended IP Reachability = TLV (135). We would then need to make the link attributes sub-TLV = applicable to this TLV (and it=E2=80=99s MT brother). > TLV 141 =E2=80=9CInter-AS reachability information=E2=80=9D seems be = one appropriate TLV to include this sub-TLV, but it requires the IS-IS = TE deployment, and is not suitable for describing the passive/stub link = on edge router. > =20 > In summary, it seems put this attribute into the =E2=80=9CPrefix = Attribute Flags=E2=80=9D sub-TLV which can be included in TLV = 135,235,236 and 237 (Extended IP reachability, MT IP. Reach, IPv6 IP. = Reach, and MT IPv6 IP. Reach TLVs) is more applicable? It would seem to me that what you=E2=80=99re describing is an attribute = of a link, not of a prefix, thus I would favor it remaining a link = attribute. But that=E2=80=99s just me. :-) Tony --Apple-Mail=_2464CEED-AD95-4366-8D0C-427F300E5086 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 <html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; = charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; line-break: after-white-space;" class=3D""><div = class=3D""><br class=3D""></div>Hi Aijun,<div class=3D""><br = class=3D""></div><div class=3D""><br class=3D""><div><blockquote = type=3D"cite" class=3D""><div class=3D""><div class=3D"WordSection1" = style=3D"page: WordSection1; caret-color: rgb(0, 0, 0); font-family: = Helvetica; font-size: 14px; font-style: normal; font-variant-caps: = normal; font-weight: normal; letter-spacing: normal; text-align: start; = text-indent: 0px; text-transform: none; white-space: normal; = word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: = none;"><div style=3D"margin: 0cm 0cm 0.0001pt; font-size: 12pt; = font-family: =E5=AE=8B=E4=BD=93;" class=3D""><span lang=3D"EN-US" = style=3D"font-size: 10.5pt; font-family: Calibri, sans-serif; color: = rgb(31, 73, 125);" class=3D"">For the link attributes that defined in = RFC5029, as that stated in<span = class=3D"Apple-converted-space"> </span></span><span lang=3D"EN-US" = class=3D""><a href=3D"https://tools.ietf.org/html/rfc5029#section-2" = style=3D"color: purple; text-decoration: underline;" = class=3D"">https://tools.ietf.org/html/rfc5029#section-2</a>,<span = class=3D"Apple-converted-space"> </span></span><span lang=3D"EN-US" = style=3D"font-size: 10.5pt; font-family: Calibri, sans-serif; color: = rgb(31, 73, 125);" class=3D"">this sub-TLV is included in the TLV = 22(Extended IS Reachability).<span = class=3D"Apple-converted-space"> </span><o:p = class=3D""></o:p></span></div><div style=3D"margin: 0cm 0cm 0.0001pt; = font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" class=3D""><span = lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: Calibri, = sans-serif; color: rgb(31, 73, 125);" class=3D"">As I read the IANA code = point<span class=3D"Apple-converted-space"> </span></span><span = lang=3D"EN-US" class=3D""><a = href=3D"https://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-code= points.xhtml#isis-tlv-codepoints-22-23-25-141-222-223" style=3D"color: = purple; text-decoration: underline;" = class=3D"">https://www.iana.org/assignments/isis-tlv-codepoints/isis-tlv-c= odepoints.xhtml#isis-tlv-codepoints-22-23-25-141-222-223</a><span = style=3D"color: rgb(31, 73, 125);" class=3D"">,<span = class=3D"Apple-converted-space"> </span></span></span><span = lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: Calibri, = sans-serif; color: rgb(31, 73, 125);" class=3D"">it notes this sub-TLV = can be included in all of these TLVs (22,23,25,141,222,223).<span = class=3D"Apple-converted-space"> </span><o:p = class=3D""></o:p></span></div><div style=3D"margin: 0cm 0cm 0.0001pt; = font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" class=3D""><span = lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: Calibri, = sans-serif; color: rgb(31, 73, 125);" class=3D""><o:p = class=3D""> </o:p></span></div><div style=3D"margin: 0cm 0cm = 0.0001pt; font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" = class=3D""><span lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: = Calibri, sans-serif; color: rgb(31, 73, 125);" class=3D"">But, when the = interface is configured as passive/stub, it seems that the above TLVs = will not be advertised, because there is no IS neighbor on this passive = link. <span = class=3D"Apple-converted-space"> </span></span></div></div></div></bl= ockquote><div><br class=3D""></div><div><br class=3D""></div><div>Fair = point. Given that there is an IP address and prefix on that link, it = would be very reasonable to advertise the Extended IP Reachability TLV = (135). We would then need to make the link attributes sub-TLV applicable = to this TLV (and it=E2=80=99s MT brother).</div><div><br = class=3D""></div><br class=3D""><blockquote type=3D"cite" class=3D""><div = class=3D"WordSection1" style=3D"page: WordSection1; caret-color: rgb(0, = 0, 0); font-family: Helvetica; font-size: 14px; font-style: normal; = font-variant-caps: normal; font-weight: normal; letter-spacing: normal; = text-align: start; text-indent: 0px; text-transform: none; white-space: = normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; = text-decoration: none;"><div style=3D"margin: 0cm 0cm 0.0001pt; = font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" class=3D""><span = lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: Calibri, = sans-serif; color: rgb(31, 73, 125);" class=3D""><o:p = class=3D""></o:p></span></div><div style=3D"margin: 0cm 0cm 0.0001pt; = font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" class=3D""><span = lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: Calibri, = sans-serif; color: rgb(31, 73, 125);" class=3D"">TLV 141 =E2=80=9CInter-AS= reachability information=E2=80=9D seems be one appropriate TLV to = include this sub-TLV, but it requires the IS-IS TE deployment, and is = not suitable for describing the passive/stub link on edge router.<o:p = class=3D""></o:p></span></div><div style=3D"margin: 0cm 0cm 0.0001pt; = font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" class=3D""><span = lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: Calibri, = sans-serif; color: rgb(31, 73, 125);" class=3D""><o:p = class=3D""> </o:p></span></div><div style=3D"margin: 0cm 0cm = 0.0001pt; font-size: 12pt; font-family: =E5=AE=8B=E4=BD=93;" = class=3D""><span lang=3D"EN-US" style=3D"font-size: 10.5pt; font-family: = Calibri, sans-serif; color: rgb(31, 73, 125);" class=3D"">In summary, it = seems put this attribute into the =E2=80=9CPrefix Attribute Flags=E2=80=9D= sub-TLV which can be included in TLV 135,235,236 and 237 (Extended IP = reachability, MT IP. Reach, IPv6 IP. Reach, and MT IPv6 IP. Reach TLVs) = is more applicable?</span></div></div></blockquote><br = class=3D""></div></div><div><br class=3D""></div><div>It would seem to = me that what you=E2=80=99re describing is an attribute of a link, not of = a prefix, thus I would favor it remaining a link = attribute.</div><div><br class=3D""></div><div>But that=E2=80=99s just = me. :-)</div><div><br class=3D""></div><div>Tony</div><div><br = class=3D""></div></body></html>= --Apple-Mail=_2464CEED-AD95-4366-8D0C-427F300E5086-- --===============5547584854968804324== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Lsr mailing list [email protected] https://www.ietf.org/mailman/listinfo/lsr --===============5547584854968804324==--