Block a host

Hi,
My AGB started getting spam regulary, and the only header info on comment box is Host: xeon.resolve.ru.

As you mentioned in other topics, I checked it from http://www2.dnstools.com, info is as below.

Will it be enough if I only ban 72.232.106.169? Or do I have to ban a range? And do ı have to ban those nserver things?

Thnx

xeon.resolve.ru resolves to 72.232.106.169
Domain Whois Results:

% By submitting a query to RIPN's Whois Service
% you agree to abide by the following terms of use:
% http://www.ripn.net/about/servpol.html#3.2 (in Russian)
% http://www.ripn.net/about/en/servpol.html#3.2 (in English).

domain: RESOLVE.RU
type: CORPORATE
nserver: rslv5.resolve.ru. 72.36.223.45
nserver: rslv6.resolve.ru. 72.36.245.126
state: REGISTERED, DELEGATED
person: Dmitriy G Danilev
phone: +7 905 2006861
fax-no: +7 812 7406861
e-mail: dmitry@resolve.ru
e-mail: abuse@resolve.ru
e-mail: ipnet@resolve.ru
registrar: REGTIME-REG-RIPN
created: 2004.10.04
paid-till: 2007.10.04
source: TC-RIPN

Can anyone help me pls?

if thats the IP it's coming from then block the IP.