May 2005
Intermediate to advanced
666 pages
21h 5m
English
book
SSH, The Secure Shell: The Definitive Guide, 2nd Edition
by Daniel J. Barrett, Richard E. Silverman, Robert G. Byrnes
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Forwarding
Forwarding (or tunneling) is the use of SSH to protect another network service. We discuss it in detail in Chapter 9, but here we describe the available serverwide configuration options.
5.7.1 Port Forwarding
SSH’s forwarding (or tunneling) features protect other TCP/IP-based applications by encrypting their connections. We cover forwarding in great detail in Chapter 9, but we introduce here the serverwide configuration keywords for controlling it.
TCP port forwarding can be enabled or disabled by the keyword AllowTcpForwarding, with the value yes (the default) or no:
AllowTcpForwarding no
Tectia can specify this more selectively for particular users or
Unix groups, with the keywords AllowTcpForwardingForUsers, AllowTcpForwardingForGroups, DenyTcpForwardingForUsers, and DenyTcpForwardingForGroups:
# Tectia
AllowTcpForwardingForUsers smith
AllowTcpForwardingForGroups students
DenyTcpForwardingForUsers evildoer
DenyTcpForwardingForGroups badguysThe values for these keywords use the same syntax as for
AllowUsers, AllowGroups, DenyUsers, and DenyGroups, respectively: [5.5.1] [5.5.2]
# Tectia with zsh_fileglob or traditional regex syntax
AllowTcpForwardingForUsers good*@*.friendly.org,*@\i10.1.2.*,12[[:digit:]]
DenyTcpForwardingForGroups bad*,33[[:digit:]]
# Tectia with egrep regex syntax
AllowTcpForwardingForUsers good.*@.*\.friendly\.org,.*@\i10\.1\.2\.*,12[[:digit:]]
DenyTcpForwardingForGroups bad.*,33[[:digit:]]Tectia’s ForwardACL keyword provides the most precise ...
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.