TCP Ports for Exchange 2003 - 2010 Coexistence

Should port 25 be open between Exchange 2003 (single server) and our 2 Exchange 2010 Hub/CAS servers during coexistence?

Ex2003 is on our 10.x.x.x old network, and Ex2010 servers on 172.x.x.x new network. Both networks have been bridged together, however when I test Mail Flow should port 25 be open bi-directional on the firewall between the two environments?
LVL 2
CTCRMInfrastructure EngineerAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

parv kumarengineerCommented:
Yes , it should be open.
Manikandan NarayanswamySecurity Specialist & IBM Security GuardiumCommented:
Hi,

Yes port 25 must be opened. However for your ready reference i am pasting the required ports which are need to be opened for Exchange 2003/2007 to coexist with Exchange 2010

Port

Protocol

808 (TCP)

Mailbox Replication Service uses to communicate

53 (TCP)

DNS

135 (TCP)

RPC End Point

389 (TCP)

LDAP

3268

LDAP

1024 > (TCP)

if mailbox store is not statically configured then 1024 higher ports need to be open

88 (TCP)

Kerberos

445 (TCP)

Microsoft-DS Service

443 (TCP)

Mailbox Replication Proxy service uses port 443 to communicate with other Exchange 2010 client access server via HTTPS.

For more information on what ports are used by Exchange 2003 & 2013. Refer the below links

https://technet.microsoft.com/en-us/library/bb124075(EXCHG.65).aspx
https://technet.microsoft.com/en-us/library/bb331973.aspx

Thanks
Manikandan

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
CTCRMInfrastructure EngineerAuthor Commented:
Thanks Guys
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Exchange

From novice to tech pro — start learning today.