Re: GNU Elpa not reachable (possibly OT)

[Robert Pluim <rpluim@gmail.com>]

Joost Kremers <joostkremers@fastmail.fm> writes:

> On Tue, Feb 19 2019, Robert Pluim wrote:
>> That does sound like some kind of networking issue, although
>> elpa.gnu.org was down for a while.
>
> It's apparently up again, but my problem hasn't gone away.
>
>> tcpdump -i any 'host 209.51.188.89 or host 2001:470:142:5::89'
>
> ```
> joost@IdeaPad:~$ sudo tcpdump -i any 'host 209.51.188.89 or host
> 2001:470:142:5::89'
> [sudo] password for joost:
> tcpdump: verbose output suppressed, use -v or -vv for full protocol
> decode
> listening on any, link-type LINUX_SLL (Linux cooked), capture size
> 262144 bytes
> 10:13:19.903664 IP6 IdeaPad.39970 > 2001:470:142:5::89.https: Flags
> [S], seq 2316084917, win 28800, options [mss 1440,sackOK,TS val
> 24582028 ecr 0,nop,wscale 7], length 0
> 10:13:20.917576 IP6 IdeaPad.39970 > 2001:470:142:5::89.https: Flags
> [S], seq 2316084917, win 28800, options [mss 1440,sackOK,TS val
> 24583042 ecr 0,nop,wscale 7], length 0
> 10:13:22.933580 IP6 IdeaPad.39970 > 2001:470:142:5::89.https: Flags
> [S], seq 2316084917, win 28800, options [mss 1440,sackOK,TS val
> 24585058 ecr 0,nop,wscale 7], length 0
> ^C
> 3 packets captured
> 3 packets received by filter
> 0 packets dropped by kernel
> ```
>
> This is after calling `M-x list-packages` in Emacs. I let it run for a
> few minutes at least, but this was all that tcpdump reported.
>
> I have no idea what you can tell from this dump, but do let me know if
> you think it's something on my end.

Itʼs not responding on IPv6. Probably because it doesnʼt have that
IPv6 address configured, which its admins will be doing at some
point. If you'd left it longer you'd have seen it trying IPv4, and
failing, which is an Emacs problem.

The only workaround I can suggest in the interim is to use its IPv4
address explicitly in package-archives, ie

(setq package-archives '(("gnu". "https://209.51.188.89/packages/")))

which will probably elicit warnings from the network-security-manager,
but in this particular case they're harmless.

Robert