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LPIC-2 202-450 study materials
LPIC-2 202-450 study resources

LPIC-2 202-450: Network Client Management

LPIC-2 202-450 · Work through your exam, one topic at a time.

All guide sections

Network Client Management

Network Client Management covers DHCP and centralized authentication clients: PAM, LDAP, and SSSD. The exam checks whether you can configure a client to obtain addressing and authenticate against a directory without breaking local logins.

Core rules

  • dhcpd.conf uses subnet, range, option routers, option domain-name-servers, default-lease-time, and max-lease-time. Fixed addresses use a host stanza with hardware ethernet and fixed-address. dhcpd -t tests syntax; leases are in dhcpd.leases.
  • PAM stacks in /etc/pam.d/ are read top-down. Module types are auth, account, password, and session; controls include required, requisite, sufficient, and optional. pam_unix handles local files; pam_ldap or pam_sss adds directory auth.
  • LDAP client config uses URI, BASE, and TLS settings in /etc/ldap/ldap.conf (or /etc/openldap/ldap.conf). SSSD uses /etc/sssd/sssd.conf with id_provider, auth_provider, and ldap_uri; start sssd and test with getent passwd user.
  • Keep a local fallback: a broken LDAP/SSSD stack can lock out SSH if PAM has no sufficient pam_unix path.

Worked example

Reserve 192.0.2.50 for a printer with MAC 00:11:22:33:44:55 in a 192.0.2.0/24 scope. Add host printer { hardware ethernet 00:11:22:33:44:55; fixed-address 192.0.2.50; } inside the subnet, ensure the dynamic range excludes .50, run dhcpd -t, reload. Reasoning: the server matches the MAC before offering a dynamic lease; an address inside the pool can cause conflicts unless excluded.

Traps

Missing semicolons in dhcpd.conf; forgetting authoritative on the only DHCP server; PAM module order that lets requisite deny before a later sufficient; LDAP TLS certificates not trusted; and SSSD not enabled/started, so getent never sees directory users.