[Odsh]

Let's say I want to hack a host A, which has a nested host B for example for security.

For host A, I can take my time and Probe + Backdoor Entry so that I can enter the host (if I succeed with those tests) without raising an alarm (if I don't glitch) and without having my OS that starts increasing each round while I'm inside the host (thanks to Backdoor Entry's specificities).

Now I'm inside host A and I want to enter host B. I could repeat the same procedure as above, however there is the small annoyance of the patrol IC that will attempt to spot me with a Perception check every minute while I Probe my way around. This gets much worse if you apply Banshee's optional rule for the Probe's duration:

Optional - the interval should be 1 hour not 1 minute … or at least 10 or 15 minutes

In which case, my chances of remaining undetected and not raising an alarm are quite slim.

The alternative is to Brute Force my way inside Host B. In which case, I'll immediately raise an alarm too.

So, am I missing something, or is it really hard to hack nested hosts without triggering an alarm?

[Xenon]

If you establish a direct connection to any device slaved to host B (it sound as if most security devices such as cameras, maglocks, sensors, alarms, scanners, etc will be part of this host) then you can probe the host directly without first having access or entering any of the hosts in the outer layers of the "onion".

Also, there are scenarios where you don't even need access on the host to begin with. Say you walk up to a locked door and the maglock is slaved to host B and is not exposed on the public facing side of the host? Establish a direct connection to the maglock and just Spoof a one and done command to it (such as "Open!"). No need to have any access on the security network in this case.

[Xenon]

I wrote this. Might be useful reading?

https://reddit.com/r/Shadowrun/comments/glxddw/the_matrix_in_sr6/

Disclaimer - it was written a few months before the Matrix FAQ was released and doesn't have the same official stamp as the Matrix FAQ. But I think most of it is still relevant :-)

[Stainless Steel Devil Rat]

Let's say I want to hack a host A, which has a nested host B for example for security.

For host A, I can take my time and Probe + Backdoor Entry so that I can enter the host (if I succeed with those tests) without raising an alarm (if I don't glitch) and without having my OS that starts increasing each round while I'm inside the host (thanks to Backdoor Entry's specificities).

Now I'm inside host A and I want to enter host B. I could repeat the same procedure as above, however there is the small annoyance of the patrol IC that will attempt to spot me with a Perception check every minute while I Probe my way around. This gets much worse if you apply Banshee's optional rule for the Probe's duration:

Optional - the interval should be 1 hour not 1 minute … or at least 10 or 15 minutes

In which case, my chances of remaining undetected and not raising an alarm are quite slim.

The alternative is to Brute Force my way inside Host B. In which case, I'll immediately raise an alarm too.

So, am I missing something, or is it really hard to hack nested hosts without triggering an alarm?

Well you might be missing that you can't swap ASDF stats mid-hack (pg. 178).

So if you backoor one host, presumably you have Sleaze higher than Attack... which complicates Brute Forcing from there.

The case of burrowing through a nested hierarchy is an example of when you might find Brute Force/Attack the more attractive option... of course your OS will be worse.  So you pick your pros/cons.

If you DO want to Probe/Backdoor, then yes it's going to take a while.  That's the point: you spare your OS, at cost of taking more in-game time!

If you don't want to run your OS up by maintaining simultaneous access thru a series of hosts nor do you want to take the time to probe successive hosts, another option besides Brute Forcing your way thru is to establish a direct connection to the host via tapping a device controlled by that host.

TL;DR:  Yes, nesting a host does inherently increase the challenge of hacking it.

[Odsh]

I wrote this. Might be useful reading?

https://reddit.com/r/Shadowrun/comments/glxddw/the_matrix_in_sr6/

Thanks for the link, I already read that one. And I confirm it is useful 

I forgot about the direct link option, good point. But this requires being "on site".

Well you might be missing that you can't swap ASDF stats mid-hack (pg. 178).

So if you backoor one host, presumably you have Sleaze higher than Attack... which complicates Brute Forcing from there.

The case of burrowing through a nested hierarchy is an example of when you might find Brute Force/Attack the more attractive option...

Indeed. But that just supports my point that hacking nested hosts is more likely to raise an alarm...

If you don't want to run your OS up by maintaining simultaneous access thru a series of hosts nor do you want to take the time to probe successive hosts, another option besides Brute Forcing your way thru is to establish a direct connection to the host via tapping a device controlled by that host.

It's not that I don't want to take time to probe. It's that while doing so, I'm likely going to get spotted by the Patrol IC and raise an alarm anyway!
And I wouldn't mind maintaining simultaneous accesses through a series of hosts if said accesses were obtained through Backdoor Entry, since in that case the OS doesn't increase over time.

I take note of the direct link option, but the Decker in my games won't like it one bit since he envisions hacking everything from a secure location. I recently gm'ed a game where they needed to infiltrate an "offline" facility. He felt trapped in a situation he didn't want to be in and didn't appreciate that game too much.

Ah well, raising a matrix alarm doesn't necessarily mean that they suspect runners on site "in the flesh", nor that the physical security suddenly get's reinforced. So it's just a complication for the hacker that is to be expected and doesn't jeopardize the run too much.

[Stainless Steel Devil Rat]

...I take note of the direct link option, but the Decker in my games won't like it one bit since he envisions hacking everything from a secure location...

That is probably the kernel of all your problems.  your player is not holding a realistic expectation... the game is literally designed to encourage the decker to go in with the team when an infiltration occurs.  You'll run into too many things that will frag over a decker who wants to remain remotely located.  Offline hosts, Noise from wireless negation, nested architectures... they all serve the meta-purpose of encouraging the decker to physically go in and THEN hack.... because frankly you end up being punished if you don't.

[Xenon]

You are not forced to use nestled hosts. If it fit you and your table better to have remote hacking with single hosts architecture where the host is always wireless accessible then you should probably seriously consider that option. And try to challenge the decker in other ways. Its your table. Your rules :-)

[Michael Chandra]

So there's basically 3 sliders to the difficulty.
- Host Rating and how the attributes are distributed
- Spider / No Spider (No Spider means no mental attributes)
- Single Host / Nested Hosts

With Nested Hosts, you're absolutely right that it heavily increases the risk, especially when Probing. This is exactly why the Decker should accompany the team and sneak in, so they can find a terminal connected to the Nested Host and skip one or two layers of security.