Network Host Status
A weekly table of ARPANET host reachability tests and status reports.
Westheimer, E., "Network Host Status", RFC 376, DOI 10.17487/RFC0376, August 1972, <https://www.rfc-editor.org/info/rfc376>.
@misc{rfc376,
series = {Request for Comments},
number = 376,
howpublished = {RFC 376},
publisher = {RFC Editor},
doi = {10.17487/RFC0376},
url = {https://www.rfc-editor.org/info/rfc376},
author = {E. Westheimer},
title = {{Network Host Status}},
pagetotal = 5,
year = 1972,
month = aug,
} RFC text
Network Working Group Ellen Westheimer
NIC # 11118 BBN
RFC # 376 8 August 1972
Categories: F, G.3
Updates: RFC #370
Obsoletes: None
NETWORK HOST STATUS
This RFC reports on the status of most Network Hosts from
July 31 to August 4.
Several Hosts are currently excluded from the daily testing
as they are presently intended to be users only. Included here
are the Terminal IMPs, which are presently in the Network (AMES,
MITRE, RADC, NBS, ETAC, USC, GWC, NOAA, SAAC, ARPA, and BBN*).
This category also includes the Network Control Center computer
(Network address 5) which is used solely for gathering statistics
from the Network. Finally, included among these Hosts are the
following:
Network
Address Site Computer
------- ---- --------
7 Rand IBM-360/65
73 Harvard PDP-1
138 Lincoln TSP
12 Illinois PDP-11
19 NBS PDP-11
23 USC IBM-360/44
The tables on the next two pages summarize the Host status
for this period.
NOTE: Ellen Westheimer left BBN to return to school on August 4.
We therefore will discontinue the publication of these summaries.
It is my understanding that UCLA-NMC is considering the publica-
tion of similar, although more detailed, survey data in the near
future; I hope that data will serve in lieu of these reports. In
addition, of course, MIT-DMCG has had survey information available
on line for some time (see RFC #308, NIC 9259.)
- Alex McKenzie -
_______________
*The BBN Terminal IMP (Network Address 158) is a prototype and
as such is frequently not connected to the Network, but being
used to refine and debug the Terminal IMP programs.
STATUS OR
PREDICTIONS
ADDRESS SITE COMPUTER STATUS OR PREDICTION OBTAINED FROM
------- ---- -------- -------------------- -------------
1 UCLA SIGMA-7 Sever #Limited Jon Postel
65 UCLA IBM-360/91 NETRJS now Bob Braden
(Telnet in June)
2 SRI (NIC) PDP-10 Server Jim White
66 SRI (AI) PDP-10 Server Len Chaiten
3 UCSB IBM-360/75 Server Ron Stoughton
4 UTAH PDP-10 Server Barry Wessler
*5 BBN (NCC) DDP-516 Never Alex McKenzie
69 BBN (TENEX-A) PDP-10 Server Dan Murphy
133 BBN (TENEX-B) PDP-10 Server(Exper.) Dan Murphy
6 MIT (Multics) H-645 Server Mike Padlipsky
70 MIT (DM) PDP-10 Server Bob Bressler
134 MIT (AI) PDP-10 Server Jeff Rubin
198 MIT (ML) PDP-10 Server Jeff Rubin
*7 RAND IBM-360/65 User Only Eric Harslem
71 RAND PDP-10 Server Eric Harslem
8 SDC IBM-370/155 Server Bob Long
9 HARVARD PDP-10 Server Bob Sundberg
*73 HARVARD PDP-1 User Only Bob Sundberg
10 LINCOLN IBM-360/67 "Soon" Joel Winett
74 LINCOLN TX-2 Server Will Kantrowitz
*138 LINCOLN TSP User Only Tom Barkelow
11 STANFORD PDP-10 Server Andy Moorer
12 ILLINOIS PDP-11 User Only John Cravits
13 CASE PDP-10 July Charles Rose
14 CARNEGIE PDP-10 Server Hal VanZoeren
15 AMES ILLIAC Server John McConnell
(PDP-10)
16 AMES IBM-360/67 "Soon" Wayne Hathaway
*144 AMES TIP User Only
*145 MITRE TIP User Only
*146 RADC TIP User Only
*19 NBS PDP-11 User Only Robert Rosenthal
*147 NBS TIP User Only
*148 ETAC TIP User Only
*23 USC IBM-360/44 User Now James Pepin
*151 USC TIP User Only
*152 GWC TIP User Only
*153 NOAA TIP User Only
*154 SAAC TIP User Only
*156 ARPA TIP User Only
*158 BBN TIP User Only
(Prototype)
_______________
*Host not included in daily testing.
#The NMC is a research site and would like
to have a prior arrangement with each user.
NO. SITE DATE AND TIME (EASTERN)
--- ---- -----------------------
7/31 8/1 8/2 8/3 8/4
1400 1830 1330 1500 1330
1 UCLA-NMC H O O O O
65 UCLA-CNN* O O O O O
2 SRI-ARC O O O O O
66 SRI-AI D D O T O
3 UCSB-MOD75 O O O O O
4 UTAH-10 O O O O O
69 BBN-TENEX O T T O R
133 BBN-TENEXB #D #T #T #T #D
6 MIT-MULTICS O T O O O
70 MIT-DMCG O H O O O
134 MIT-AI O H O O O
194 MIT-ML O H T O O
71 RAND-CSG D O O O O
8 SDC-ADEPT #D D #D #D #D
9 HARVARD-10 O O O D O
10 L.L.-360 H T H H R
74 L.L.-TX-2 O O O R O
11 STANFORD-AI H H H H T
13 CASE D D D D D
14 CMU-10 O O O D O
15 AMES-ILLIAC D T D D D
16 AMES-67 D H D D D
where
D = Dead (Destination Host either dead or inaccessible [due to
network partitioning or local IMP failure] from the BBN Terminal
IMP.)
F = Full (Destination Host opened a connection, informed user that
all Network ports were in use, and immediately closed the connection.)
H = 1/2 Open (Destination Host opened a connection but then either
immediately closed it, or did not respond any further.)
O = Open (Destination Host opened a connection and was accessible to users.)
R = Refused (Destination Host returned a CLS to the initial RFC.)
T = Timed out (Destination Host did not complete the ICP and open a
connection within 60 seconds.)
_______________
*The only service currently offered by the UCLA IBM-360/91 is a Network
Job Service (NETRJS), however, the BBN Terminal IMP is not equipped to
test NETRJS. We are assuming that initial connection to the NETRJS
logger indicates that NETRJS is also functioning.
#These sites advertise that they may not have their system available
at these times.
[ This RFC was put into machine readable form for entry ]
[ into the online RFC archives by BBN Corp. under the ]
[ direction of Alex McKenzie. 1/97 ]
ISO Plain Language
On this page
§1Hosts Included in the Report
The report covers most network hosts from July 31 to August 4. Some hosts are excluded from daily tests because they are intended to be users only, including listed Terminal IMPs and the Network Control Center computer used to gather statistics.
The tables list host addresses, sites, computers, reported status or prediction, and the source of that information.
The report covers hosts tested during the stated period. It leaves out some machines used only to access the network or gather statistics.
§2Status and Prediction Table
The first table gives a status or prediction for each listed host, such as Server, User Only, Soon, Never or a limited service. It also identifies the person who supplied the information.
The report explains that the UCLA IBM-360/91 offered NETRJS, which the BBN Terminal IMP could not test. For that host, the report assumes that a connection to the NETRJS logger indicates the service works.
The table combines reported service information with an estimate of whether a host is available. Some entries are not direct results of the daily connection test.
§3Daily Test Results
The second table shows a result for each tested host on five dates. Open means the host opened a connection and was accessible; half open means it opened and then closed or stopped responding; full means it reported all network ports in use; refused means it returned CLS; timed out means no ICP and connection completed within 60 seconds; dead means the host was inaccessible from the BBN Terminal IMP.
A hash marks sites that said their systems might not be available at those times.
Each test result has a letter that describes what happened during connection setup. For example, Open means a host accepted the connection, while Timed out means setup did not finish within 60 seconds.
- OOpen — Host opened a connection and was accessible to users.
- HHalf open — Host opened a connection but closed it or stopped responding.
- FFull — Host said all network ports were in use and closed the connection.
- RRefused — Host returned a CLS to the initial RFC.
- TTimed out — ICP and connection were not completed within 60 seconds.
- DDead — Host was dead or inaccessible from the BBN Terminal IMP.
§4End of This Series
The note says Ellen Westheimer left BBN on August 4 and that publication of these summaries would therefore stop. Alex McKenzie says UCLA-NMC was considering similar, more detailed survey data and points to online survey information at MIT-DMCG in RFC 308.
The author says the summaries will stop after the person preparing them leaves BBN. The note points to other host-survey information.