Local Network Area
Essay 16
Local Area Networks
Marshall D. Abrams and Harold J. Podell
L ocal area n e t w ork (L AN) communicat io ns s ecurity is address ed in t his essay. LANs are introduc ed as providing: (1) a privat e communicat io ns facility, (2) s ervic es ov er a r elativ ely limit ed g e ographic area, (3) a high dat a rat e for comput er communicat io ns, and (4) common acc ess t o a wid e rang e of d evice s and s ervic es.
S ecurity issu es p ert in e nt t o L ANs ar e discuss e d. For e xampl e ,
LANs shar e many s ecurity probl ems and approach es for t h eir solut io ns wit h poi nt -t o-poi nt co nv e nt i o nal com municatio ns syst ems. In addit io n, L ANs hav e som e uniqu e probl e ms of t h eir ow n:
(1) univ ersal dat a availability, (2) passiv e a nd act iv e wir et ap t hr eat s, (3) e nd-t o- e nd acc ess control, and (4) s ecurity group control.
Count erm easur es i nclud e physical prot ect io n, and s eparat io n by physical, logical, and e ncryptio n m et h ods. Trust ed N et w ork Int erfac e Units, e ncryption, and k ey distribut io n are also discuss ed.
Exampl es ar e discuss ed t o illustrat e t h e diff er e nt approach e s t o L AN s ecurity. T h e e x ampl es i n t his essay are a composit e of s ev eral e xisting product f eat ur es, s el ect ed t o dem o nstrat e t h e us e of e ncryption for co nfid e nt iality, and trust ed syst em t ec h n ology for a local area n e t w ork.
L oca l area net w o rk techn o l ogy/t op o l ogy o ver v ie w
T h is essay addr ess es L AN s ecurity from t h e vi e w poi nt of open systems interconnection ( O SI). T hat is, w e focus o n t h e s e v e n-lay er O SI prot ocols
(illustrat ed in Figure 1); in fact, w e co nc e n trat e o n t h e low er lay ers. T his focus follo ws t h e hist ory of LANs; t hat is, t h e O SI communicatio ns probl ems had t o b e solv ed b ef or e open systems could be addr ess ed.
It is usually not good form t o st art a n essay by discussi ng what is
Local Area Networks
Marshall D. Abrams and Harold J. Podell
L ocal area n e t w ork (L AN) communicat io ns s ecurity is address ed in t his essay. LANs are introduc ed as providing: (1) a privat e communicat io ns facility, (2) s ervic es ov er a r elativ ely limit ed g e ographic area, (3) a high dat a rat e for comput er communicat io ns, and (4) common acc ess t o a wid e rang e of d evice s and s ervic es.
S ecurity issu es p ert in e nt t o L ANs ar e discuss e d. For e xampl e ,
LANs shar e many s ecurity probl ems and approach es for t h eir solut io ns wit h poi nt -t o-poi nt co nv e nt i o nal com municatio ns syst ems. In addit io n, L ANs hav e som e uniqu e probl e ms of t h eir ow n:
(1) univ ersal dat a availability, (2) passiv e a nd act iv e wir et ap t hr eat s, (3) e nd-t o- e nd acc ess control, and (4) s ecurity group control.
Count erm easur es i nclud e physical prot ect io n, and s eparat io n by physical, logical, and e ncryptio n m et h ods. Trust ed N et w ork Int erfac e Units, e ncryption, and k ey distribut io n are also discuss ed.
Exampl es ar e discuss ed t o illustrat e t h e diff er e nt approach e s t o L AN s ecurity. T h e e x ampl es i n t his essay are a composit e of s ev eral e xisting product f eat ur es, s el ect ed t o dem o nstrat e t h e us e of e ncryption for co nfid e nt iality, and trust ed syst em t ec h n ology for a local area n e t w ork.
L oca l area net w o rk techn o l ogy/t op o l ogy o ver v ie w
T h is essay addr ess es L AN s ecurity from t h e vi e w poi nt of open systems interconnection ( O SI). T hat is, w e focus o n t h e s e v e n-lay er O SI prot ocols
(illustrat ed in Figure 1); in fact, w e co nc e n trat e o n t h e low er lay ers. T his focus follo ws t h e hist ory of LANs; t hat is, t h e O SI communicatio ns probl ems had t o b e solv ed b ef or e open systems could be addr ess ed.
It is usually not good form t o st art a n essay by discussi ng what is