[HECnet] Thousands of DECnet errors on Tops-20

AB 00 00 03 00 00 is the All Routers address. It is likely a router sending a Hello message advertising its presence, presumably coming from node 63.779. Regards Rob From: owner-hecnet at Update.UU.SE <owner-hecnet at Update.UU.SE> On Behalf Of Thomas DeBellis Sent: 11 January 2021 19:33 To: HECnet <hecnet at Update.UU.SE> Subject: [HECnet] Thousands of DECnet errors on Tops-20 I was wondering if anybody else had either seen the below or noticed it. I didn't have as free space on my public structure as I thought I should, so I went poking around and found: TOMMYT:<SYSTEM-ERROR> Pages Bytes(Size) Write Date and Time Writer ERROR.SYS.1;P777752 138,495 70909216(36) 11-Jan-2021 14:20:29 OPERATOR To put this into perspective, we are looking at about a 304 MB file; it's larger than what could have been held on an RP06 So I ran SPEAR and pulled down a few of the most recent items, viz: *********************************************** DECNET ENTRY LOGGED ON 9-Jan-2021 19:02:18-EST MONITOR UPTIME WAS 113 day(s) 0:50:12 DETECTED ON SYSTEM # 3691. RECORD SEQUENCE NUMBER: 28063. *********************************************** DECNET Event type 5.15, Receive failed Line NI-0-0 Failure reason = Frame too long Ethernet header = AB 00 00 03 00 00 / AA 00 04 00 FF 0B There are hundreds of thousands of these, causing ERROR.SYS to grow by a number of pages every day. I didn't remember how to turn a DECnet node number into dotted decimal, but I did notice the follow from the DECnet bridge (SIGUSR1): Host table: 0: purgatorio 0.0.0.0:0 (Rx: 2963632 (3352330) Tx: 1687334 Fw: 1276298 (Drop rx: 2076032)) Active: 1 Throttle: 598 (203) 1: legato 108.65.195.50:4711 [Ov: 0, Nov: 1693548, Lst: 0] (Rx: 1687334 (1693548) Tx: 1276298 Fw: 1687334 (Drop rx: 6214)) Active: 1 Throttle: 9054(070) Hash of known destinations: aa000400080a -> 0 (2.520) aa0004000a0a -> 0 (2.522) aa000400ff0b -> 1 (2.1023) So one of these is coming over that bridge (2.1023). What is AB 00 00 03 00 00? Anybody have any ideas of what's going on? I haven't looked in the monitor code, yet. If you are running any 36 bit OS, what are you seeing?