My List Mail wrote:
> thanks guys,
> 
> i already blocked the youtube using firewall rule
> 
> 208.65.153.0/24
> thanks :)
> 
> how will i know the correct CIDR if it has bigger ip range address?

Oh, use whois, perhaps?  Which would give you the correct block
as
	208.65.152.0/22

arf 223> whois  208.65.152.0

OrgName:    YouTube, Inc.
OrgID:      YOUTU
Address:    71 E Third Ave
Address:    2nd Floor
City:       San Mateo
StateProv:  CA
PostalCode: 94401
Country:    US

NetRange:   208.65.152.0 - 208.65.155.255
CIDR:       208.65.152.0/22
NetName:    YOUTUBE
NetHandle:  NET-208-65-152-0-1
Parent:     NET-208-0-0-0-0
NetType:    Direct Assignment
NameServer: DNS1.SJL.YOUTUBE.COM
NameServer: DNS2.SJL.YOUTUBE.COM
Comment:
RegDate:    2006-03-02
Updated:    2006-03-09

RTechHandle: NETWO1084-ARIN
RTechName:   networkradbaccount
RTechPhone:  +1-650-343-2960
RTechEmail:  radb at youtube dot com

OrgTechHandle: NETWO1084-ARIN
OrgTechName:   networkradbaccount
OrgTechPhone:  +1-650-343-2960
OrgTechEmail:  radb at youtube dot com

# ARIN WHOIS database, last updated 2006-09-05 19:55
# Enter ? for additional hints on searching ARIN's WHOIS database.