Network host status
An ARPANET host status report covering September 30 to October 8, 1971
Westheimer, E., "Network host status", RFC 252, DOI 10.17487/RFC0252, October 1971, <https://www.rfc-editor.org/info/rfc252>.
@misc{rfc252,
series = {Request for Comments},
number = 252,
howpublished = {RFC 252},
publisher = {RFC Editor},
doi = {10.17487/RFC0252},
url = {https://www.rfc-editor.org/info/rfc252},
author = {E. Westheimer},
title = {{Network host status}},
pagetotal = 3,
year = 1971,
month = oct,
} RFC text
Network Working Group E. Wentheimer
Request for Comments: 252 Bolt, Beranek and Newman
Category: F, G.3 8 October 1971
NIC: 7696
The purpose of this RFC is to report on the recent status of most
Network Hosts. During September 27 through September 29 the BBN
prototype Terminal IMP (Network Address 158) was inaccessible due to
hardware debugging. The Network was, therefore, not examined on
these days.
Three Hosts which were not officially able to act as Server's at the
time of RFC #240 are now able to do so. These Hosts are:
NETWORK SITE COMPUTER
ADDRESS
2 SRI (NIC) PDF-10
6 MIT (Multics) H-645
9 HARVARD PDP-10
The Harvard PDP-10, however, has limited core space. They will,
therefore, run the Telnet program only occasionally.
The following two tables summarize the information on the Host status
for September 30 - October 8.
NETWORK SITE COMPUTER DAY, DATE AND TIME (Eastern)
ADDRESS TH F M Tu W Th F
9/30 10/1 10/4 10/5 10/6 10/7 10/8
1100 1753 1200 1600 1100 1300 1530
1 UCLA SIGMA-7 O T D O #D O O
*65 UCLA IBM-360/91 O O D O D O O
2 SRI(NIC) PDP-10 O #D T #T O T #D
66 SRI(AI) PDP-10 D D D D D D D
3 UCSB IBM-360/75 D O O O O O O
4 UTAH PDP-10 D D D D D D D
69 BBN(TENEX) PDP-10 T T O O O D D
6 MIT(Multics)H-645 O O D T D T T
70 MIT(DM) PDP-10 D H D T D T T
8 SDC IBM-360 D D D D D D D
9 HARVARD PDP-10 T D T D D T T
10 LINCOLN IBM-360 H H H H D T D
where
D = Dead (Destination Host either dead or inaccessible [due to
network partitioning or local IMP failure] from the BBN Terminal
IMP.)
R = Refused (Destination Host returned a CLS to the initial RFC.)
T = Timed out (Destination Host did not respond in any way to the
initial RFC, although not dead.)
H = 1/2 Open (Destination Host opened a connection but then
either immediately closed it, or did not respond any further.)
0 = Opened (Destination Host opened a connection and was
accessible to user.)
* The UCLA IMB-360/91 currently has Remote Job Service (NETRJS),
but has not implemented a full server Telnet System. The BBN
Terminal IMP is not equipped to test NETRJS however, we are
assuming that receipt of the UCLA explanatory message indicates
that NETRJS is also functioning.
# These sites advertise that they may not have their system
available # at these times.
NETWORK SITE COMPUTER STATUS or "STATUS or PREDICTIONS"
ADDRESS PREDICTION OBTAINED FROM
1 UCLA SIGMA-7 Server Jon Postel
65 UCLA IBM-360/91 Remote Job
Service now,
Telnet in April Bob Braden
2 SRI(NIC) PDP-10 Server John Melvin
66 SRI(AI) PDP-10 November Len Chaiten
3 UCSB IBM-360/75 Server Jim White
4 UTAH PDP-10 "Soon" Barry Wessler
5 BBN(NCC) DDP-516 Never Alex McKenzie
69 BBN(TENEX) PDP-10 Server Dan Murphy
6 MIT(Multics)H-645 Server Mike Padliosky
70 MIT(DM) PDP-10 Server Bob Bressler
7 RAND IBM 360/65 User only Eric Harslem
71 RAND PDP-10 January Eric Harslem
8 SDC IBM-360/67 "Soon" Bob Long
9 HARVARD PDP-10 Server Bob Sundberg
73 HARVARD PDP-1 User only Bob Sundberg
10 LINCOLN IBM-360 "Soon" Joel Winnet
74 LINCOLN TX2 Uncertain Tom Barkalow
11 STANFORD PDP-10 November Andy Moorer
12 ILLINOIS PDP-11 User only John Cravits
13 CASE PDP-10 December 15 Charles Rose
14 CARNEGIE PDP-10 January Hal VanZoeren
15 PAOLI B6500 Uncertain John Cravits
16 AMES TIP User only
17 MITRE TIP User only
18 BBN(TIP) Prototype TIP User only
[This RFC was put into machine readable form for entry]
[into the online RFC archives by Kelly Tardif, Via Genie 10/1999]
ISO Plain Language
On this page
§1The Reporting Period and New Servers
The report covers host status from September 30 through October 8. The BBN prototype Terminal IMP was unavailable from September 27 through September 29 while hardware debugging took place, so the network was not examined on those days.
Three hosts that had not been officially able to act as servers at the time of RFC 240 were now able to do so: SRI NIC's PDP-10, MIT Multics' H-645 and Harvard's PDP-10. The report notes Harvard's limited core space meant it would run Telnet only occasionally.
The report covers the listed test days and notes why there are no tests for the previous three days. It also says three hosts could now serve other sites.
§2Daily Test Results
The table gives the date, Eastern time and result of tests for each listed host. O means the host opened a connection and was accessible to a user. D means dead or inaccessible from the BBN Terminal IMP; T means it did not respond, although it was not dead.
R means the host refused the initial request. H means the host opened a connection but immediately closed it or stopped responding. The report marks some sites that said their system might not be available at those times.
Each table entry describes one attempted connection. The letter codes say whether the host was accessible, unreachable, timed out, refused the request, or only partly opened a connection.
§3Operator Predictions
A separate table lists host status or predictions supplied by site operators. It includes entries such as Server, User only, Soon and dates, along with the person who supplied the information.
The unit metadata records RFC 255 as the document that later obsoleted RFC 252.
The report also records what operators said about their hosts' roles or expected availability. RFC 255 later replaced it.