1Y0-350 · Question #122
A network engineer needs to configure load balancing for an FTP site. Which type of session persistence method can the engineer select for this scenario?
The correct answer is B. Source IP. See the full explanation below for the reasoning.
Question
A network engineer needs to configure load balancing for an FTP site. Which type of session persistence method can the engineer select for this scenario?
Options
- ARule
- BSource IP
- CCookie Insert
- DCustom Server ID
How the community answered
(38 responses)- A5% (2)
- B74% (28)
- C16% (6)
- D5% (2)
Community Discussion
13
Ingrid P.Jan 3, 2026Source IP persistence is the right call here because FTP uses two separate TCP connections, a control channel and a data channel, and cookies cannot be set on non-HTTP traffic, so the only reliable way to pin both connections to the same backend server is by hashing the client's source IP address. Rule and Custom Server ID do not handle the multi-connection nature of FTP, and Cookie Insert is strictly an HTTP/HTTPS method.
Imani T.Jan 4, 2026Solid breakdown, though the one thing worth flagging for exam purposes is that source IP persistence breaks down in NAT-heavy environments where multiple clients share a single public IP, which can create backend hotspots and undermine the whole point of having multiple servers.
Luis F.Jun 26, 2026Source IP persistence is the right answer here, option B. FTP is not HTTP so you cannot use cookies at all, which rules out C right away, and Custom Server ID (D) is for HTTP responses where the server tags itself. Rule-based persistence (A) works for more advanced HTTP/HTTPS conditions and would not make sense for a plain FTP flow. With Source IP persistence the NetScaler hashes the client IP address and always sends that client to the same back-end server, which is exactly what FTP needs because the control connection and data connection both come from the same client IP and have to land on the same server to work properly.
Hiroshi T.Jun 28, 2026Source IP persistence is correct, but worth noting that if clients share a NAT gateway you can end up with all of them pinned to one server, so in NAT-heavy environments you might also look at whether the NetScaler supports NTLM or RADIUS persistence as a fallback approach.
Mateus R.Jun 26, 2026Source IP persistence is like a bouncer at a club who stamps your hand and always waves you back to the same table, so your whole visit stays connected to one server, which is exactly what FTP needs since it opens a separate control channel and data channel that both have to land on the same box. Cookie Insert and Rule options sound tempting, but think about why FTP would reject one of them entirely, before you look at the right answer.
Imani T.Jan 7, 2026Source IP persistence is the right call here, and it makes sense when you think about how FTP actually works. FTP opens two separate TCP connections, a control channel on port 21 and a data channel on a negotiated port, so the load balancer needs a way to tie both connections back to the same server. Source IP persistence does exactly that by hashing the client's IP address and always sending that client to the same backend, which keeps both channels landing in the right place. Cookie Insert is off the table because FTP has no concept of HTTP cookies, and Custom Server ID is specific to certain proprietary setups that do not apply to a general FTP load balancing scenario.
Ingrid P.Jan 10, 2026Source IP persistence is solid for active mode FTP, but in passive mode the data channel originates from the client to a server-chosen port, so the same source IP hash still routes correctly, which is worth spelling out since people often conflate active and passive mode when they first encounter this on the exam.
Kemal J.Jun 26, 2026Source IP persistence is the right call here because FTP uses two separate TCP connections, control on 21 and data on 20, and you need both to land on the same backend server or the transfer falls apart. Cookie insert won't work since FTP has no HTTP layer to carry a cookie, and that rules out most of the other session tricks too.
Luis F.Jun 29, 2026Yeah Kemal nailed the core of it, just worth adding that in active mode FTP the data connection actually originates from the server back to the client on port 20, so the persistence really has to account for that reverse flow too, not just client-to-server traffic.
Hiroshi T.Jun 23, 2026Source IP persistence is the right call here. FTP uses two separate TCP connections (control on port 21 and data on port 20), so Cookie Insert is off the table because FTP is not HTTP, and Source IP ties both connections from the same client address to the same backend server, keeping the session intact across both channels.
Ola B.Jun 24, 2026Source IP persistence is solid for FTP, but worth noting it can break down in environments where multiple clients share a single NAT address, so if that is a concern in your setup you may want to lean on a dedicated FTP proxy or sticky sessions at the firewall level instead.
Ola B.Jun 26, 2026Source IP is your only real choice for FTP since there is no HTTP layer for cookies to ride on. I almost second-guessed myself toward Cookie Insert on test day but caught it right before clicking.
Hiroshi T.Jun 29, 2026Source IP persistence is the go-to for FTP, but worth noting that if the exam scenario mentions a NAT device upstream, multiple clients can appear as a single IP and break affinity, so keep that caveat in mind for scenario-based questions.