> On Jul 29, 2023, at 11:59 AM, Quentin Armitage <[email protected]> > wrote: > > Many thanks for making the changes in versions 08 and 09. > > On Fri, 2023-07-28 at 18:53 -0700, Acee Lindem wrote: >> Hi Quentin, >> >> Thanks much for your detailed review!!! See inline. I’m posting version -08. >> >> Thanks, >> Acee >> >>> On Jul 28, 2023, at 09:03, Quentin Armitage <[email protected]> wrote: >>> >>> >>> 29. Section 5.2.4 third paragraph add sentence at end "Note, each Virtual >>> Router for a >>> VRID >>> should be configured with different priorities (unless there are more than >>> 254 non >>> address- >>> owner virtual routers) since if two (or more) Backup Routers are configured >>> with the same >>> priority, when the Active Router fails, both Backup Routers will transition >>> to be an >>> Active >>> Router simultaneously, both sending VRRP advertisements and gratuitous >>> ARP/unsolicited ND >>> messages, causing confusion for learning bridges (see section 3)". >> >> >> Nope. The primary address is used as a tie-breaker. > > I understand that the primary address is used as a tie-breaker, but it is > highly undesirable > for two or more Backup Routers to transition to be Active Router > simultaneously, which is > what happens if the Active Router shuts down or fails and there is more the > one Backup > Router with the next highest priority. In my proposed additional sentence > "virtual router" > should be "Virtual Router" and "should" should be "SHOULD"; it is advice on > how to avoid > problems (as set out above) when the Active Router stops operating and two or > more Backup > Routers promote themselves. My view is that it is a configuration error to > configure the > same Priority on more than one Virtual Router, but the primary address > tie-breaker is a work > around to the problem the enables the VRRP protocol to continue functioning.
This will be covered in 8.3.2 (your other Email). I added a reference. > >> >>> >>> 52. Section 6.4.1 after (775) add "(778) @ Send an advertisement" (the >>> reason for this is >>> to >>> update/correct any learning bridges caches and to make the lower priority >>> Active Router >>> revert to Backup state. This is a change in procedure but not a protocol >>> change). >> >> I don’t think the virtual router transitioning to Backup Router should send >> an advertisement >> here. > > (775) is in the else block of the if check at (725) to (735), and so applies > to the higher > priority (or equal priority and higher IP address) Active Router, and is > therefore the > router that remains in Active state. I believe it is important for the Active > Router > remaining in the Active state to send an advert immediately after receiving a > lower priority > advert, otherwise learning bridges will forward packets to the wrong router > until the > Adver_Timer expires on the higher priority Active Router. I guess it is better to err on the side of faster convergence as this event should only happen immediately following a transition (unless there are other problems in the network). > > > I have the following comments regarding version 09. > > 1. Section 1.7 Virtual Router MAC Address change "ethernet" to "Ethernet". Fixed. > > 2. Section 3 I think if "configurable to < 1 second" is changed to > "configurable to < 1/25 > second" gives a better impression of how quickly VRRP can operate (1/25 is 4 > * 10ms - > minimum Advertisement_Interval). I incorrectly specified 1/64 in my previous > email since for > some bizarre reason I had in mind that the minimum Advertisement_Interval was > 1/256 second). Okay - although this level of precision wasn’t intended here. > > 3. Section 6.5 (455) delete newly inserted "and Skew_Time" - it duplicates > the new (452) and > Skew_Time must be calculated before Active_Down_Interval. Thanks - this was a typo as I thought about combining the steps but forgot to remove it when I added (452). > > 4. Section 7.1 penultimate paragraph the first "Max Advertisement Interval" > should be "Max > Advertise Interval" since it is a field in the received VRRP packet, and the > second "Max > Advertisement Interval" should be "Advertisement_Interval" since it is a > parameter of the > Virtual Router. Fixed. > > 5. Section 8.3.2 second paragraph delete ", especially if preemption is set" > since it > implies that more than on Virtual Router may be configured with priority 255, > which not only > contradicts the proceeding paragraph, and due to the definition of Priority > implies that > more than 1 Virtual Router is the address owner (apologies - I should have > included this in > my previous email). > > > With regards, > > Quentin Armitage > _______________________________________________ rtgwg mailing list [email protected] https://www.ietf.org/mailman/listinfo/rtgwg
