Hosts using the IMP Going Down message
A request for Hosts to notify users about an impending local IMP outage.
Walden, D.C., "Hosts using the IMP Going Down message", RFC 548, DOI 10.17487/RFC0548, August 1973, <https://www.rfc-editor.org/info/rfc548>.
@misc{rfc548,
series = {Request for Comments},
number = 548,
howpublished = {RFC 548},
publisher = {RFC Editor},
doi = {10.17487/RFC0548},
url = {https://www.rfc-editor.org/info/rfc548},
author = {D.C. Walden},
title = {{Hosts using the IMP Going Down message}},
pagetotal = 1,
year = 1973,
month = aug,
} RFC text
Network Working Group D. Walden
RFC # 548 BBN-NET
NIC # 17794 August 16, 1973
Hosts Using the IMP Going Down Message
As given in BBN Report 1822 (Specifications for the Interconnection
of a Host and an IMP), IMP to Host message type 2 specifies that the IMP
local to the Host is going down; the message further says when the IMP
is going down, for how long, and why.
When the IMP goes down after sending the IMP Going Down message to
the Host, the Host's network users and local users of the network will
not, in general, be forewarned unless the Host sends a message to these
users. We therefore urge all Hosts to warn their network users and
users of the network of impending IMP downs; just logging the received
IMP Going Down message on a logging teletype, as many Hosts currently
do, seems insufficient.
Incidentally, please remember that Tuesday mornings from 7 a.m. to 9
a.m. (Eastern Time) are reserved for Network Software Maintenance, as
announced in RFC #440.
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ISO Plain Language
On this page
§1The IMP Going Down Message
BBN Report 1822 defines IMP-to-Host message type 2 as the IMP Going Down message. It tells the Host when the local IMP will go down, for how long, and why.
The IMP sends its Host a message about an upcoming shutdown. The message includes when it will happen, how long it will last, and why.
§2Hosts Should Warn Their Users
The RFC says users will not generally be forewarned unless the Host sends them a message. It urges Hosts to warn both network users and local users of the network when they receive the IMP Going Down message.
The author says merely logging the received message on a teletype, as many Hosts did, seems insufficient.
Hosts should pass the outage warning on to their users. Simply recording it on a teletype does not reliably warn people.
§3Network Software Maintenance Window
The RFC reminds readers that Tuesday mornings from 7 a.m. to 9 a.m. Eastern Time are reserved for Network Software Maintenance, as announced in RFC 440.
The notice reminds readers of a regular network software maintenance window. It is Tuesday from 7 to 9 a.m. Eastern Time.