CCI through Firewall r11

CCI through Firewallr11

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Objectives

-CCI Considerations for NSM r11 deployment in DMZ

-Review different deployment options

-Review potential Risks , primarily Denial of Service (DOS) attacks


DoS

-Any software deployed in DMZ requires protection against malicious access or denial of service attacks. This requires review of security solutions to prevent these attacks which is out of scope of this presentation


Agenda

- CCI Introduction

- CCI Layers

- DoS

- Different Deployment Options


The need for CCI

- Applications, such as Job Management Agent, Event Management, etc., need to communicate with one another across various servers and platforms.


The need for CCI

- Allows applications on various platforms to communicate with applications on any other using the mechanism of CCI.


CCI is available on...

- UNIX

- NT

- AS/400

- OpenVMS

- Tandem

- OS/390


What CCI does….

- Allows applications to communicate with one another without considering IPC / network programming issues.

- Presents set of APIs that allow programmers to focus on what an application needs to do and forget about IPC / network programming issues.


CCI Layers

- QUES Layer introduced the ability to connect at send time.

- RMT Layer connects at CCI start up time.- RMT has auto-connect capability- Auto-connect capability can be disabled with configuration setting


QUES Layer

- Eliminates need for configuration files

- New hosts may be brought into configuration with less effort

- Removal of host from configuration does not affect other hosts

- Connections between hosts are short lived

- Bi-Directional CCI Initialization


QUES Layer

- Requires 7001 port to be unblocked bi-directional

- CCI Initialization from DMZ and Private Network

- Potential risk for Denial of Service Attacks

- Syn Flooding

- Etc

- Port must be unblocked for the designated NSM servers and not for all hosts

- No predefined source port


QUES Layer

- Transport mechanism

- Connects with SYN Flag

- Send Data

- Disconnect

- No persistent connection


RMT Layer

- Persistent Connection

- Connection established at start up and remains open for duration of CCI

- Preferred option in Firewall deployment

- New hosts may be brought in with Auto Connect Feature


RMT Layer

- Port Usage

- Source Port can be configured by environment settings

- Destination port defaults to 1721 but can be configured


Syn Three-way Handshaking

DMZ Private

DMZ Private

DMZ Private

SYN

SYN/ACK

ACK


How SYN Flooding Works

- A TCP connection request (SYN) is sent to the target computer. The source IP address in the packet can be "spoofed," or replaced with an address that is not in use on the Internet, or that belongs to another computer. An attacker may send many of these TCP SYNs to tie up as many resources as possible on the target computer to exhaust the resources

- Upon receiving the connection request, the target computer allocates resources to handle and track the new connection, then responds with a "SYN-ACK". In this case, the response is sent to the "spoofed" non- existent IP address.

- No response is received to the SYN-ACK. A default-configured Windows NT 4.0 computer will retransmit the SYN-ACK 5 times, doubling the time-out value after each retransmission. The initial time-out value is three seconds, so retries are attempted at 3, 6, 12, 24, and 48 seconds. After the last retransmission, 96 seconds are allowed to pass before the computer gives up on receiving a response, and deallocates the resources that were set aside earlier for the connection. This can be configured using registry changes

BLOCK 7001 port except for designated NSM servers


Firewall SYN Flood

- Review Firewall solution to prevent Syn Flood attacks or DoS

- Ensure, 7001 is only unblocked for the two NSM servers which requires CCI Connectivity


CCI Ports – Windows

- Transporter

- Quenetd

- TCP destination port 7001 for Windows to Windows communication

- CCI will attempt TCP connection first- If fails, will then attempt, RMT daemon on 1721


CCI

- Transporter Service - QUES Layer- TCP 7001

- Verify Transport Protocols settings to TCP to avoid attempts to open 7003 or 7004

- Transport Protocol defaults to TCP


Firewall Setup

DMZ

Secured


Testing Environment

Deployment Options


- We want to forward Event exception messages from DMZ without installing the Ingres Client in the DMZ environment

- How can we configure this?

Scenario 1Scenario 1


Deployment - Scenario 1

- Install Event Agent

- Set Event Agent Proxy Node to NSM server inside the firewall

- Open up CCI 7001 port bi-directional.


DMZ Event DSB

- Event Agent Proxy Node

- Specify the node name of Central Server Event Manager

- DSB refreshed from Central Server


DMZ Event DSB

- If proxy node not required, then local dsb can be pushed to DMZ by other means


Common Services

DSM EVT

Windows -> Windows

TCP 7001 FIREWALL

7001 Unblocked both directions – CCI may be initiated from DMZ

7001 Unblocked both directions – CCI may be initiated from DMZ

DSMwvdbt

Common Services

EVT

MDB

DMZ

Secured Zone

TCP 7001


- We want to open CCI port for outbound traffic only and prevent CCI initialization from taking place in the DMZ

- How can we configure this?

Scenario 2Scenario 2


Scenario 2

- RMT daemon provides persistent connection

- Customize ccirmtd.rc to start up connection from secured network

- Add the Windows servers to RMTHOSTNAME entries


Windows – Windows RemoteRMTHOSTS

Add Windows node to RMTHOSTS settings for DMZ and secured servers

Secured Node

DMZ


Windows – Windows RemoteRMTHOSTS- Update RMTHOSTS on both Windows nodes.- If only one node is updated, the other Windows node will use the QUES layer. For example:- RMTHOSTS entry on DMZ node not updated to use RMT layer for secured zone node

- Secured server RMTHOSTS entry updated to use RMT layer for DMZ node.

- All requests from secured to DMZ will use RMT.- Events from DMZ to secured will use QUES layer. This port would be blocked. It will then attempt to use RMT port.


ccirmtd.rc location

- ccirmtd.rc must reside in ca_appsw directory - NOT caiuser directory (as in previous releases)


Windows – Windows RemoteSecured ccirmtd.rc

Add Windows node to ccirmtd.rc to prevent potential first autoConnect attempt failure. The CCIRMTD.rc in the secured network must be updated to startup RMT connection


Windows – Windows RemoteDMZ ccirmtd.rc- CCIRMTD.rc file on the DMZ must have entry with nostart and retry=0 (no retry).

- This prevents CCI initialization from DMZ environment


Windows – Windows RemoteSource Port- To pre-define source port for RMT connection, add environment variable CAI_CCI_PORT1


Source Port


Inbound CAM port Blocked


CAM Inbound

CAM inbound traffic denied if CAM not initiated from secured zone


Common Services

DSM EVT

Windows -> Windows Remote

FIREWALL

MDB

7001 Blocked-

Persistent Connection and traffic initiated from Private network

7001 Blocked-

Persistent Connection and traffic initiated from Private network

DSMwvdbt

Common Services

EVT

DMZ

Secured Network

TCP 1721


DMZ -> Secured


- Client would like to use QUES Layer but wish to block 7001 port from DMZ to private network.

- What are the implications?

Deployment - Scenario 3Deployment - Scenario 3


DMZ -> Secured

- Execute cawto in DMZ environment to send message to Private network

- Cawto [<secured>] Sending message from DMZ to Private

- Message will be denied by Firewall

- Exception messages cannot be forwarded from DMZ to secured network


DMZ -> Private with 7001 Blocked


Summary

- For Windows – Windows, use Ques Layer with 7001 unblocked for the selected NSM servers only. CCI Initialization from DMZ and Secured environment

- For Windows – Windows , configure RMT layer to avoid by-directional unblocking of ports

- For Windows –> Unix or UNIX -> Windows (including Linux) , RMT layer provides persistent connection


Questions and Answers

Any questions?Any questions?

CCI through Firewall r11

Documents

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