nanog mailing list archives
Re: Is there any data on packet duplication?
From: Sabri Berisha <sabri () cluecentral net>
Date: Mon, 22 Jun 2020 23:14:45 -0700 (PDT)
----- On Jun 22, 2020, at 10:21 PM, Saku Ytti saku () ytti fi wrote: Hi,
Metro: S1-S2-S3-S1 PE1: S1 PE2: S2 Customer: S3 STP blocking: ANY S3 sends frame, it is unknown unicast flooded, S1+S2 both get it (regardless of which metro port blocks), which will send it via PE to Internet. STP doesn't help, at all. Hope this helps.
Yeah, except that unless you use static ARP entries, I can't come up with a plausible scenario in which this would happen for NTP. Assuming we're talking about a non-local NTP server, S3 will not send an NTP packet without first sending an ARP. Yes, your ARP will be flooded, but your NTP packet won't be transmitted until there is an ARP reply. By that time MACs have been learned, and the NTP packet will not be considered BUM traffic, right? That said, I have seen packet duplication in L2 onlu networks that I've worked on myself, but that was because I disregarded a lot of rules from the imaginary networking handbook. Thanks, Sabri
Current thread:
- Is there any data on packet duplication? Hal Murray (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? William Herrin (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? Mark Tinka (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? Mark Tinka (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? Mark Tinka (Jun 22)
- Re: Is there any data on packet duplication? William Herrin (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? Sabri Berisha (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? Sabri Berisha (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 22)
- Re: Is there any data on packet duplication? William Herrin (Jun 22)
- Re: Is there any data on packet duplication? Saku Ytti (Jun 23)
- Re: Is there any data on packet duplication? Karsten Thomann via NANOG (Jun 23)
- Re: Is there any data on packet duplication? Hal Murray via NANOG (Jun 23)