5.  Functi

      S the facilities intrimplemented. An imp the eff4.3BSD was t y b acilities.

5.1.  Kernel Extensi

      A significant effthe netw the kernel. The w fixing bugs, tuning the algand revamping the l the system t

5.1.1.  Subnets, Br

      Tand ashiThis facility allspace int f-site hsubnetwhas been rew envir

      The default Internet br ied with a h all The br ace basis.

5.1.2.  Interface Addressing

      The netw aces has been rewnetw aces nceach interface c addresses assigned t ace. This permits a single interface t at the same time as XNS pr

      The Address Resfhas been made m lexible by allact as an ``clearing h nm the ARP translaticache and may interactively interr y the cache's c

5.1.3.  User C Netw fering

      Alth ault am buffering f ile system dumps t it fr icant increases in buffering [Walsh84]. The sets P system call has been extended tIn additi Igets P and sets P, are n aced t ic

5.1.4.  Number File Descript

      T ull use the many descriptthe previ 30 iles per prThe changes entailed generalizing select t 32-bit w ile descript rthe page table entries, and limiting m the linear scans a pr ile table. The default per-pr rth file descript

5.1.5.  Kernel Limits

      Many internal kernel c iguratim icatiThe limit rand the limit 15 m ile systems has been changed tThe maximum file system size has been increased tnumber prand per pr data and 64 megabyte stack. Nthe default limits f with 4-8 megabyte physical mem

5.1.6.  Mem

      The glhand that was used bThe first time that it enc erence bit. If the reference bit was still clear it wThe use a single hand dmem the hand can take up tBy the time the hand gets arthe infDuring peri sudden shthe page daem ind any reclaimable pages until it has c ull revTthe clThe fr erence bits, the back hand f pages behind reclaiming pages that still have cleared reference bits. While the cthe hands t suitable f

      The c igurati the virtual mema significant understanding its simple tasks as increasing the maximum prThis pr icantly imprc iguratican be specified using a single igurati ile. Standard c igurati 17, 33 and 64 megabytes.

5.1.7.  Signals

      The 4.2BSD signal implementati alternate signal stack. The 4.3BSD implementatithe entire signal handler's state is nAnthat it used an und rUsers c r4.3BSD f ies the sigreturn system call.

      Many existing prThe restartable system call semantics 4.2BSD signals caused many these prT y p pr r eri UNIXthe sigvec system call has been extended spr y that system calls are nrestarted after particular signals.

5.1.8.  System L

      A system l acility has been added that sends kernel messages tsysl printing The revised scheme feliminates the time lag in updating the messages file, unifies the f kernel messages, pr iner granularity cthat get printed and eliminates the degradati lRecusing this facility. Mhave been m ied trather than writing directly

5.1.9.  Wind

      The tty structure has been augmented tinf an assThese sizes can be t the screen they are manipulating. When these sizes are changed, a new signal, SIGWINCH, is sent the current prThe edit ied ttheir view the wnacrOther pr the screen have been m ied t acility as well.

5.1.10.  C igurati UNIBUS Devices

      The UNIBUS c igurati igurati dedicated UNIBUS memThe new r y the c igurati memand c the UNIBUS.

5.1.11.  Disk Rec r

      The MASSBUS disk driver's err ixed tretry befand c ter earlier c er. The err

5.2.  Functi

      M the changes tall pr pr

5.2.1.  Name Server

      In 4.2BSD the name res Igeth P, getservbyname, etc.) were implemented by a set database files maintained lInc iles resulted in inaccessibility hIn 4.3BSD these files may be replaced by a netwinsure a c the name space in a multimachine envirThis name server f

5.2.2.  System Management

      A new utility, rdist, has been prall their machines up t sA master set sNew versi getty, init, and l P merge the functi several files int lexibility in the startup pr

      The new utility timed keeps the time c(within a single LAN) synchrIt dthe rate time advance withIt nIf the master dies Other machines may participate in a purely slave r

5.2.3.  R

      Many bugs in the r ixed; it is cand nsubnets and pIts ficient by tuning with the use executi iles, al cusing the kernel's inline

5.2.4.  C

      The symb Idbx has had many new features added, and all the kn ixed. In additi Idbx has been extended tThe f If77 has had numer ixed. The C c ied sgenerate single precisi l