FortiADC
Layer 2 ADC
Features
IPv4 only
Balances traffic among multiple next hop gateways
HTTP content inspection and modification like Layer7 load Balancing
Useful when the ADC doesn't know the real server IP addresses
Layer 4 Virtual Servers
Features
IPv4 and v6
Fast inspection (processed on the first packet)
Persistence (based on L4 objects like IP addresses)
Load Balancing (based on L4 objects like IP addresses)
NAT (based on L4 objects like IP addresses)
Destination NAT is the default method of forwarding the traffic
**
Layer 4 ADC simply forwards the traffic to the real server and doesn't terminate the TCP handshake!
Layer 7 Virtual Servers
Features
IPv4 and v6
slower inspection then Layer 4
HTTP content inspection and modification
Persistence
Load balancing
routing based on L7 objects (headers, cookies, etc)
**
Layer 2 and 7 ADC proxies the TCP connection !
Virtual Server objects
Virtual Server (Mandatory)
Real Server Pool (Mandatory)
Real Servers (Mandatory)
Health Check (Optional)
Load Balancing Method (Mandatory)
Application Profile (Mandatory)
HTTP caching (Optional)
HTTP compression (Optional)
Server Persistence (Optional)
Content Routing (Optional)
HTTP content rewrite (Optional)
HTTP error page (Optional)
Health Check Methods
ICMP / TCP echo
Send an ICMP / TCP echo request and waits for a response
HTTP/S
queries the sever by sending either a GET or a HEAD request
Response content can be evaluated
TCP
Confirms that the TCP 3-way handshake can be completed to a specific TCP port
DNS
Send a DNS A record request and expects a specific IP address as a response
Radius / Radius Accounting / SMTP /POP3 / IMAP4
Log in to the server usinf a specified protocol
FTP
checks for a specific file on the FTP server
SNMP
polls the server for CPU, memory and disk usage. The server is deemed unresponsive if it does not reply, or if any of those usage values goes above a preconfigured threshold.
TCP Half Open
Send a SYN and waits for a SYN/ACK. When its recieved, RST is sent
TCP SSL
Establishes SSL connection. The result of the SSL connection determines the status of the server
Can be used for any SSL-based protocol
Application Profiles
TCP, UDP and FTP profiles
need to have a session timeout value
HTTP profile
(client address )By default it uses the client IP to setup the connection with the backend server
(client address )If x-forward for is enabled, FortiADC uses it to setup the connection with the backend server
disbaling this causes FortiADC to use its own address (SourceNAT)
HTTP Turbo
can't use advanced features such as source NAT, caching, compression, rate limiting, content rewrite.
Load Balancing Methods
Error Page
Can only be used with layer 7 virtual servers
web page needs to be uploaded as a html.index with a zip file
Global Server Load Balancing GSLB
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