I started to monitor this mailing list one week ago, so please don't flame me if something of this is "old stuff". We at RUS run two GigaRouters and one GRF400 with a variety of HiPPI, ATM OC3c, FDDI, and Ethernet. Here is a very nasty thing we found on the GigaRouter: (software is 4.7.18) 1. Fragmentation from HiPPI to ATM (HiPPI IP routing) When 65280 bytes HiPPI packets get fragmented to fit ATM MTU, data is (randomly?) corrupted. We proved inserted zero's with an ATM tester. This ruins TCP performance and makes NFS almost unusable. The only workaround we know is to let HiPPI send with ATM MTU. This again ruins HiPPI performance and puts additional workload on the supercomputers. (reported to Ascend support) We also found some funny things on the GRF400 you may be interested in: (software is 1.3.8) 1. Fragmentation from HiPPI to ATM (HiPPI IP routing) Behaves the same as the GigaRouter BUT we found that it runs well if you set the ATM MTU to a value slightly less than 9180 bytes - say 9179 bytes. Then we saw no bad checksums on the participating hosts. (reported to Ascend support) 2. Filter daemon doesn't load new configuration sometimes We observed that the filter daemon sometime (don't know why) refuses to load its configuration when doing the kill -HUP. The entry in the gr.console only does not show the filter activation then. We found that letting the deamon reload an empty filter configuration (all commented out) and then the configuration we originally intended again, it works without rebooting the box. 3. "locked" interfaces - well configured but dead If you configure two interfaces with identical IP addresses (one taken down), the newly configured one wins and the old one gets what I name "locked". If you then configure the new interface with another IP address, the old one remaines locked. It shows up, well configured, but is dead. We found that you have to give it an IP address of a different subnet - say from some spare subnet or so - to unlock it. Then you can again assign the original IP address. We did this on the GigaRouter and the GRF400. Please comment on my points and allow some questions too: 1. Does anyone have experiences with filtering and what impact it has on the performance ? 2. Does anyone already have a GRF1600 and/or the restricted version of the OC12c interface ? 3. Anyone using HiPPI and ATM on the GigaRouter/GRF ? (IP-Routing vs. HiPPI over ATM tunnel, etc.) I would be very interested, if you could let me know. Thanks in advance, Best Regards Tassilo Erlewein -- Tassilo Erlewein Computing Center University of Stuttgart Communication Systems & BelWue Development Allmandring 30, D-70550 Stuttgart tel ++49 711 685 5871 fax ++49 711 678 7626 e-mail: erlewein@rus.uni-stuttgart.de ++ Ascend Users Mailing List ++ To unsubscribe: send unsubscribe to ascend-users-request@bungi.com To get FAQ'd: <<A HREF="http://www.nealis.net/ascend/faq">http://www.nealis.net/ascend/faq</A>> </PRE> <!--X-MsgBody-End--> <!--X-Follow-Ups--> <HR> <STRONG>Follow-Ups</STRONG>: <UL> <LI><STRONG><A HREF="msg11672.html">(ASCEND) Re: GigaRouter/GRF experiences</A></STRONG></LI> <UL> <LI><EM>From</EM>: "Neil J. McRae" <neil@DOMINO.ORG></LI> </UL> <LI><STRONG><A HREF="msg11653.html">Re: (ASCEND) GigaRouter/GRF experiences</A></STRONG></LI> <UL> <LI><EM>From</EM>: ascend@digistar.com</LI> </UL> </UL> <!--X-Follow-Ups-End--> <!--X-References--> <!--X-References-End--> <!--X-BotPNI--> <HR> <UL> <LI>Prev by Date: <STRONG><A HREF="msg11628.html">Re: (ASCEND) Getting USR Sportsters to behave...</A></STRONG> </LI> <LI>Next by Date: <STRONG><A HREF="msg11624.html">Re: (ASCEND) What good is Ascends Access Control??</A></STRONG> </LI> <LI>Prev by thread: <STRONG><A HREF="msg11669.html">Re: (ASCEND) Maxes and Bitsurfer Pro</A></STRONG> </LI> <LI>Next by thread: <STRONG><A HREF="msg11653.html">Re: (ASCEND) GigaRouter/GRF experiences</A></STRONG> </LI> <LI>Index(es): <UL> <LI><A HREF="mail2.html#11627"><STRONG>Main</STRONG></A></LI> <LI><A HREF="thrd275.html#11627"><STRONG>Thread</STRONG></A></LI> </UL> </LI> </UL> <!--X-BotPNI-End--> <!--X-User-Footer--> <!--X-User-Footer-End--> </BODY> </HTML>