Enabling Netskope Global Service Load Balancing
1. Netskope Client Version:
a. The minimum version for all Netskope Clients deployed is R99.
b. If the customer is using inline proxies, e.g. Blue Coats, R103 is required.
2. Allowlisting: In order for Netskope Clients to reach the GSLB service and to be able to perform RTT measurements against data centers, the following IP ranges must be allowlisted (port 443):
3. Endpoints with the Netskope Client must be able to resolve gateway.gslb.goskope.com
4. Netskope Clients optimally should be able to directly reach all allowlisted IP ranges. This may require modification of PAC files with any IP ranges and gateway.gslb.goskope.com.
FAQs
1. What happens for client versions less than R103?
a. R99: This release will work for customers that do not have inline proxies, e.g. Blue Coats. GSLB cannot be enabled if such proxies are in place.
b. R96.1 <= version < R99: GSLB should not be enabled when these client versions are present. Clients will be forced to use LDNS, and this can dramatically reduce performance due to inaccurate DC selection.
c. Version < R96.1: These client versions have no GSLB code, so there will no effect to enabling GSLB.
2. Does GSLB fail over to ECS0/EDNS-based GTM DC selection?
a. For Netskope Client versions >= R104, the client can fall back to EDNS then LDNS should GSLB fail for any reason.
3. What are the criteria for a Netskope Client switching DCs?
a. The Netskope Client will determine the RTT of DCs every 15 minutes.
b. A DC change may occur If there is a DC in the list with latency that is better by 25% from the current DC and the RTT delta is more than 20ms.
4. Is GSLB required for Localization Zones?
a. No. Localization Zones work with GTM as well as GSLB (although DC selection may be better with GSLB).