Re: lug-bg: Sendmail [malko utochnenie]
- Subject: Re: lug-bg: Sendmail [malko utochnenie]
- From: vlk@xxxxxxxxxxxxxxxxx (Vesselin Kolev)
- Date: Thu, 2 Jan 2003 12:10:32 +0200
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Chestita Nova Godina:))
Absoliutno syglasen sym s Todor Georgiev.
Na Mano iskam da kazha:)) che onia traceroute beshe
napraven s cel da se vidi koi e krainia dostavhick:)) no
horata sa si izdignali zashtitni barieri:)
Shto se kasae do in-addr.arpa delegiran, s uzhas moga da
zaiavia, che v BG internet prostranstvo tova e malko tema
tabu. Dosega kompetentni mnenia po vyprosa sym chul samo
ot Daniel Kalchev i Boyan Krosnov... Za mnogo dostavchici
temata in-addr.arpa e tabu, kakto porno filmite sa tabu za
monasite. Zatova i ne se chudete na ochevidnite gluposti,
koito se tvoriat i praviat..
Malko sa tezi, koito predostaviat po bezklasov pyt upravlenieto
na in-addr.arpa zapisite na svoite klienti. A kak se delegira
bezklasovo samo edin in-addr.arpa zapis e neshto nepoznato
za 90% ot systemnite administratori (strah me e da se pomislia,
che chisloto e po-goliamo). Az biah napisal edin document
predi dosta vreme po vyprosa...
http://www.lcpe.uni-sofia.bg/linuxdoc/one-in-addr.arpa/
i nishto ne stana chestno kazano. Edin pyt vlizam v IRC i
to popadam v kanal pylen s administratori... Kato im dadoh
da prochetat tova, te mi kazaha "ne mozhemi nie da si gubim
vremeto da pravim na lameri takiva extri"... ili "abe tova sa
nevyzmozhni raboti, stiga gluposti, koi si ti, che shte ni kazvash
kakvo da pravim"... Vse simvolni nizove ot tozi sort...
Ne mozhe da se ochakva da niama problemi, sled kato mnogo
hora ne razbirat kakvo e tova in-addr.arpa, kakvo e tova
bezklasovo delegirane i kakvo e tova uvazhenie kym klienta.
Dosta vulgarno zvuchi i facta, che na klient ne e predostaven
dostyp do SMTP servera na dostavchika. Tova si e napravo
podigravka spored men. Niakoi dostavchici sa napravo paranoici
i obosnovavat otkaza da predostaviat SMTP servera si za polzvane
ot strana na klientite si s glupavi i smeshni prichini. Po syshtata
logika traibva da zabraniat i vaobshte vryzkata kym Internet, zashtoto
tia mozhe da se polzva za neshto "losho".
Ot druga strana e uchudvashto kolko in-addr.arpa domaini ne sa
delegirani pravilno. Do kakvo sym trygnal da govoria za in-addr.arpa
kato i drugite domaini sa delegirani s liav izmeyznal krak vse po
'easy' shemi... kato kazhesh na tezi deto sa delegirali LAME vsichko
shto sa zahvanali se syrdiat...
Sega shte vi dam edin primer za lame delegation... Shte razgledame
domaina mail.bg:
[root@lcpe root]# whois -h whois.digsys.bg mail.bg
Registration information for the mail.bg domain name
domain: mail.bg
ogranization: Mail - M. Shumakov ET
address: 12 B, St. Karadja str., BG-1000 Sofia
admin-c: MS17891-RIPE
tech-c: MS17891-RIPE
tech-c: IT885-RIPE
name-server: ns.bdata.net
name-server: ns2.bdata.net
name-server: ns.mail.bg (193.201.172.98)
status: Registered
requested_on: 1999-11-01
registered_on: 2000-01-08
Contact information
person: MS17891-RIPE
name: Momchil Shumakov
organization: Mail - M. Shumakov ET
address: 12B St. Karadja str., BG-1000 Sofia
e-mail: momchil@xxxxxxx
phone: +359 2 9885007
fax: +359 2 9885007
person: MS17891-RIPE
name: Momchil Shumakov
organization: Mail - M. Shumakov ET
address: 12B St. Karadja str., BG-1000 Sofia
e-mail: momchil@xxxxxxx
phone: +359 2 9885007
fax: +359 2 9885007
person: IT885-RIPE
name: Ivan Tzukev
organization: Mail - M. Shumakov ET
address: 12B St. Karadja str., BG-1000 Sofia
e-mail: ivan@xxxxxxx
phone: +359 2 9885007
fax: +359 2 9885007
[root@lcpe root]#
V registera na TLD BG sa podadeni 3 servera za imena:
name-server: ns.bdata.net
name-server: ns2.bdata.net
name-server: ns.mail.bg (193.201.172.98)
Shtom tezi serveri za imena da podadeni v registera, e nuzhno
te da vryshtat pri zapitvane za NS RR autoritativni (dostoverni)
otgovori. Neka zapochnem da proveriavame autoritativnostta s
pomoshta na dig:
[root@lcpe root]# dig @ns.bdata.net -t ns mail.bg
; <<>> DiG 9.2.1 <<>> @ns.bdata.net -t ns mail.bg
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 47662
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 5
;; QUESTION SECTION:
;mail.bg. IN NS
;; ANSWER SECTION:
mail.bg. 86400 IN NS purgatory.spnet.net.
mail.bg. 86400 IN NS ns.mail.bg.
mail.bg. 86400 IN NS ns.bdata.net.
mail.bg. 86400 IN NS ns.spnet.net.
mail.bg. 86400 IN NS ns2.bdata.net.
;; ADDITIONAL SECTION:
purgatory.spnet.net. 137614 IN A 212.50.0.15
ns.mail.bg. 86400 IN A 193.201.172.98
ns.bdata.net. 86400 IN A 194.145.63.2
ns.spnet.net. 93040 IN A 212.50.0.10
ns2.bdata.net. 86400 IN A 194.145.63.13
;; Query time: 11 msec
;; SERVER: 194.145.63.2#53(ns.bdata.net)
;; WHEN: Thu Jan 2 12:32:50 2003
;; MSG SIZE rcvd: 213
[root@lcpe root]#
Tuk ima autoritativen otgovor, zashtoto ima flag "aa" v reda:
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 5
T.e. domaina mail.bg e pravilno delegiran varhu servera za imena ns.bdata.net.
Da vidim dali e taka vyrhu drugia server ns2.bdata.net:
[root@lcpe root]# dig @ns2.bdata.net -t ns mail.bg
; <<>> DiG 9.2.1 <<>> @ns2.bdata.net -t ns mail.bg
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3024
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 5
;; QUESTION SECTION:
;mail.bg. IN NS
;; ANSWER SECTION:
mail.bg. 56146 IN NS ns.bdata.net.
mail.bg. 56146 IN NS ns.spnet.net.
mail.bg. 56146 IN NS ns2.bdata.net.
mail.bg. 56146 IN NS purgatory.spnet.net.
mail.bg. 56146 IN NS ns.mail.bg.
;; ADDITIONAL SECTION:
ns.bdata.net. 86400 IN A 194.145.63.2
ns.spnet.net. 57802 IN A 212.50.0.10
ns2.bdata.net. 86400 IN A 194.145.63.13
purgatory.spnet.net. 57802 IN A 212.50.0.15
ns.mail.bg. 290696 IN A 193.201.172.98
;; Query time: 22 msec
;; SERVER: 194.145.63.13#53(ns2.bdata.net)
;; WHEN: Thu Jan 2 12:34:31 2003
;; MSG SIZE rcvd: 213
[root@lcpe root]#
Opsss.. eto go problema:
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 5
niama "aa" flag i tozi server ne dava authoritativni otgovori za domaina
mail.bg. T.e. vyrhu tozi server ima lame delegation na mail.bg. Da proverim i
tretia:
[root@lcpe root]# dig @ns.mail.bg -t ns mail.bg
; <<>> DiG 9.2.1 <<>> @ns.mail.bg -t ns mail.bg
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 4609
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1
;; QUESTION SECTION:
;mail.bg. IN NS
;; ANSWER SECTION:
mail.bg. 86400 IN NS ns2.bdata.net.
mail.bg. 86400 IN NS purgatory.spnet.net.
mail.bg. 86400 IN NS ns.mail.bg.
mail.bg. 86400 IN NS ns.bdata.net.
mail.bg. 86400 IN NS ns.spnet.net.
;; ADDITIONAL SECTION:
ns.mail.bg. 86400 IN A 193.201.172.98
;; Query time: 10 msec
;; SERVER: 193.201.172.98#53(ns.mail.bg)
;; WHEN: Thu Jan 2 12:35:45 2003
;; MSG SIZE rcvd: 149
[root@lcpe root]#
Tuk vsichko e nared i ima flag "aa".
T.e. domaina mail.bg e lame delegiran vyrhu servera ns2.bdata.net.
Po princip nad 20% ot vsichki domaini v TLD BG sa lame delegirani.
Za drugite TLD kato .com, .net i t.n.. polozhenieto e oshte po-otchaivashto.
Malko hora razbirat istinata, che edno e da si kupish domain, a syvsem
drugo e pravilno da go managirash.
* * *
Tova losho managirane na domain reflektira directno vyrhu kachestvoto na
uslugata "elektronna poshta"...
Bedata e, che malko sa tezi, koito se trogvat ot problemite i se opitvat
da gi razreshat...
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