1Y0-230 · Question #110
Which mode on the NetScaler can a Citrix Administrator utilize to avoid asymmetrical packet flows and multiple route/ARP lookups?
The correct answer is C. MAC-based Forwarding. MAC-based forwarding can be used to avoid multiple-route/ARP lookups and to avoid asymmetrical packet flows. https://docs.citrix.com/en-us/netscaler/11/networking/interfaces/configuring-mac-based-
Question
Which mode on the NetScaler can a Citrix Administrator utilize to avoid asymmetrical packet flows and multiple route/ARP lookups?
Options
- AUSNIP
- BLayer 3
- CMAC-based Forwarding
- DLayer 2
How the community answered
(43 responses)- A2% (1)
- B9% (4)
- C84% (36)
- D5% (2)
Explanation
MAC-based forwarding can be used to avoid multiple-route/ARP lookups and to avoid asymmetrical packet flows. https://docs.citrix.com/en-us/netscaler/11/networking/interfaces/configuring-mac-based-
Topics
Community Discussion
7
Bao N.Oct 19, 2025MAC-based Forwarding is the one you want here. MBF lets the NetScaler forward return traffic using the MAC address of the original client-side router instead of doing a fresh route and ARP lookup each time, which is exactly what kills you with asymmetric flows in multi-homed or active-active setups.
Yusuf A.Oct 23, 2025Honestly I keep coming back to A, USNIP, because my senior explained that Use Subnet IP mode lets the NetScaler forward return traffic directly without bouncing it back through the device in weird paths, which is exactly what causes those asymmetric flow headaches and extra route and ARP lookups. Anyone else locking in A on this one or am I missing something?
Bao N.Oct 24, 2025Yusuf, USNIP actually keeps the NetScaler as the source IP for server-side connections, so return traffic still comes back through it, whereas USIP (Use Source IP, option C) is what lets the server respond directly back to the original client IP and avoids those asymmetric routing problems you described.
Nina C.Oct 31, 2025Has to be D, Layer 2 keeps traffic on the same segment, no routing needed.
Bao N.Nov 1, 2025Nina, Layer 2 switching does keep traffic local but it also means every broadcast hits every device on that segment, which kills performance as you scale. C is correct because VLANs logically segment the network at Layer 2, containing broadcast domains without needing separate physical infrastructure.
Imani T.Oct 8, 2025Layer 2 mode is the move here because when the NetScaler operates at Layer 2 it stays in the same broadcast domain and forwards based on MAC addresses without having to make routing decisions, which is exactly what kills asymmetric flow problems and keeps you from hammering the route and ARP tables on every packet. I went with D on my practice run and it just makes sense from a fundamentals standpoint, Layer 2 keeps the traffic path simple and symmetric by design.
Bao N.Oct 10, 2025Imani, I hear you on the logic but C is the right pick here because Transparent mode is what actually lets the NetScaler sit in the traffic path without an IP address on the data plane, keeping flows symmetric without any routing involvement, which is a step beyond generic Layer 2 forwarding. Layer 2 mode still requires the NetScaler to participate in switching decisions in a way that can complicate asymmetric flow handling compared to true Transparent mode passthrough.