my isp has trouble with its own dhcp assignment

22_oct_17_mon 19.35.utc



howdy , folks ; long time , no post .
why ?
because , when compared to 20 - 40 years ago , when i --loved-- it ,
   email has become the most_royal of pains to use .

please forgive this brief digression ; it is relevant .

i spent 6 hours , yesterday ,
   typing a detailed account of the symptoms and
   the eventual identification of that
   which i believe to be the actual problem
   with my isp's dhcp server .

when sending ,
   i got the password wrong [ correct chars , wrong order ] .
believing that i was closing the dialog_box for the password ,
   i closed the composition window .
after wrestling w/ thunderbird for an hour w/o finding the message ,
   i resorted to the tried_and_true bsd approach ;
   with hd and vi , i found , finally , a copy in a file called "Sent" .
because the email was never sent ,
   this is the exact place in which to save it .
i believe that the jargon for this characteristic is "feature" .

ok ; so , i did not lose the 6 hours of typing [ whew ! ] .

i copied the relevant lines from "Sent" into its own file .
--but-- , for the life of me , i can not get thunderbird to
   bring this file into a new composition window ,
   except as an "attachment" [ which i can not see ] .

iirc , email_"attachment"s are strongly discouraged on this list .
so , it is --not-- included w/ this post .
how_ever , i could be wrong .
if it --is-- permissible to do so ,
   then i will be happy to send it w/ a subsequent post .



here is the abridged version of my problem .

i have built backup_hardware for my gateway box .

in the event of a hardware failure ,
   a]  power_down failed_box ,
   b]  detach cables ,
   c]  swap boxen ,
   d]  attach cables ,
   e]  power_up good_box w/ auto_boot w/ dhclient .

during the testing of the new box ,
   i have found that the isp's dhcp server returns an address
   which works only partially or not_at_all
   [ it is a different address , always ; should it be ? ] .

because the existing box has not failed ,
   ifconfig tells me its real identity .

if i use , manually , the "add" form of the ifconfig command ,
   with this address , then ,
   suddenly , everything works perfectly .

--but-- , i did this manually , not by using dhcp .
i must assume that i do not know the prior address .

the handbook and various man_pages discuss , at length ,
   the case of a roving lap_top , w/ multiple isps .
in this case , i have multiple clients and a constant isp ;
   this is not discussed .



is there a way for my client to persuade the isp's server to
   "bind" my client to an address which the isp will accept ?

what is the etiquette regarding
   email_"attachment"s in postings to this list ?

is there a way to get a text_file
   [ perhaps , created w/ vi ]
   into a thunderbird composition window ?



tia

rob