NSIP, MIP, SNIP, VIP explanation
- The NetScaler IP (NSIP) address is the IP address at which you access the NetScaler for management purposes
- The NetScaler can have only one NSIP
- The NSIP is also called the Management IP address
- You must add this IP address when you configure the NetScaler for the first time
- If you modify this address, you must reboot the NetScaler
- You cannot remove an NSIP address
- For security reasons, NSIP should be a non-routable IP address on your organization's LAN.
- Configuring the NetScaler IP address is mandatory.
- With an IPv6 address configured as the NSIP in NetScaler running on release 8.1, when upgrading from release 8.1 to 9.2 the NSIP changes to a SNIP. If you want this IPv6 address as the NSIP, you need to first delete this IPv6 address and then add this IPv6 address as the NSIP.
- Mapped IP addresses (MIP) are used for server-side connections
- A MIP can be considered a default Subnet IP (SNIP) address, because MIPs are used when a SNIP is not available or Use SNIP (USNIP) mode is disabled.
- If the mapped IP address is the first in the subnet, the NetScaler appliance adds a route entry, with this IP address as the gateway to reach the subnet
- You can create or delete a MIP during run time without rebooting the appliance.
- As an alternative to creating MIPs one at a time, you can specify a consecutive range of MIPs.
- A subnet IP (SNIP) address is used in connection management and server monitoring
- It is not mandatory to specify a SNIP when you initially configure the NetScaler appliance
- In a multiple-subnet scenario, the NetScaler IP (NSIP) address, the mapped IP (MIP) address, and the IP address of a server can exist on different subnets
- To eliminate the need to configure additional routes on devices such as servers, you can configure subnet IP addresses (SNIPs) on the NetScaler
- With Use SNIP (USNIP) mode enabled, a SNIP is the source IP address of a packet sent from the NetScaler to the server, and the SNIP is the IP address that the server uses to access the NetScaler. This mode is enabled by default.
- When you add a SNIP, a route corresponding to the SNIP is added to the routing table. The NetScaler determines the next hop for a service from the routing table, and if the IP address of the hop is within the range of a SNIP, the NetScaler uses the SNIP to source traffic to the service.
- When multiple SNIPs cover the IP addresses of the next hops, the SNIPs are used in round robin manner.
- Virtual IP address (VIP or VIPA) is an IP address assigned to multiple domain names, servers or applications residing on a single server instead of connected to a specific server or network interface card (NIC) on a server
- Incoming data packets are sent to the VIP address which are routed to actual network interfaces.
- A server IP address depends on the Media Access Control (MAC) address of the attached NIC, and only one logical IP address may be assigned per card. However, VIP addressing enables hosting for several different applications and virtual appliances on a server with only one logical IP address.
- VIP have several variations and implementation scenarios, including Common Address Redundancy Protocol (CARP) and Proxy Address Resolution Protocol (Proxy ARP).
- VIPs are mostly used to consolidate resources through the allocation of one network interface per hosted application.
- It is also used for connection redundancy by providing alternative fail-over options on one machine; A VIP address may still be available if a computer or NIC fails, because an alternative computer or NIC replies to connections.